Wednesday, 3 December 2014

Eye Dominance and Clay Pigeon Shooting

A friend of mine recently told me that he’d been invited to do some clay pigeon shooting. He was concerned that he wasn’t sure which eye he should be using when aiming.

This brings us back to our old friend, eye dominance. If you are aligning one object, such as the end of a gun, with another object, such as a clay pigeon, you can only do this accurately with one eye – the “dominant” or sighting eye – as the other eye will be slightly out of line.

If you are right-handed and right eye dominant, there’s no problem. But if your gun is in front of your right eye, and you are aligning with your left eye, your shot will slightly off target. So my first piece of advice was to check his eye dominance in something that approximated a shooting condition (some people, including myself, use different eyes to align depending on which arm is pointing). He could do this with a simple stick, held as if it were a gun, and pointed towards a distant object such as an aerial on a roof. He simply closes each eye in turn to see which is in alignment.

He discovered that when he closed his right eye he was aligned, but not when he closed his left. As he is right-handed, this would mean that his shots would be a bit to the left of the target. He could counter this by aiming slightly right of the target if it’s coming overhead. You normally need to aim in front of the clay to take into account its movement after the shot. But if the target is coming from his right he should aim straight at it; and if it is coming from his left he’d need to aim even a bit further ahead of the clay than usual.

If all that seems too complicated, a simple answer would be to close his left eye, although that’s not ideal as you do lose some perceptual information. It can, however work as a quick fix. In the event, my friend used a combination of these strategies, and he seemed to feel he got on pretty well for a beginner.

Somebody who is shooting regularly and has this “cross-dominance” problem may be able to learn to shoot left-handed. Otherwise, there are some products available. “Shotspot” is an opaque circle that you put on the centre of the lens of the dominant eye. This distorts the central image enough to make you use the non-dominant eye. Some wrap-around sunglass suppliers offer a choice of interchangeable lenses, so you can have a yellow or clear lens in front of you non-dominant eye, and a dark lens in front of your dominant one. The yellow lens might be more effective than the clear one because it will enhance the contrast, especially in poor light conditions.

For more advanced levels, there is a product called “Easy Hit!!” This is a fibre optic bead that is attached to the gun barrel. The idea of this product is to encourage the non-dominant eye to align, without disturbing the vision of the dominant eye as the shooter naturally aligns their non-dominant eye with this fluorescent bead. This therefore seems to give a more natural vision, and for £30 seems good value.

David Donner

Monday, 10 November 2014

Watch The Ball

I was recently alerted to an article by former England batsman Ed Smith. He described an occasion when he was chopping some wood with an axe. He found that when he concentrated intensely on the intended point of contact, he became clumsy. But when he relaxed and let the axe swing, whilst only casually noting the target, he landed the axe on exactly the right spot. This led him to the belief that in cricket, we talk too much about watching the ball.

My first reaction was that chopping wood is rather a different task to batting. Although when chopping you need to fixate the target to begin with, once you’ve made some incision into the wood you need to repeat the same action using muscle memory. When batting, however, you are not simply looking to repeat the previous action, as each delivery from the bowler is likely to be slightly different. Each shot must be tightly related to the path of the ball, although it’s not uncommon to see a beautiful looking drive that misses the ball by a considerable margin.

And then I recalled a match involving Old Tonbridgians that I umpired several years ago. Tonbridge were chasing a fairly modest total and, having lost an early wicket had a fruitful second wicket partnership. One player seemed full of confidence and talent, and was soon hitting seemingly decent deliveries all around the ground. By the time he was out, for about 40, the game was more than half won. The other player I recall as being older and taller and extremely courteous and polite. I thought he was a rather nervous player, as he was constantly asking for his guard to be checked (I know a few umpires who would have been very fed up with that). He really struggled at the start of his innings, being dropped off a sitter early on, and making numerous streaky shots. Once he got past about 40, he started making some nice drives, and took his side to victory with a score of about 60.

After the match, I was told that Tonbridge had an ex-England player, and I assumed it was the batsmen who had smashed the ball everywhere, but it turned out to be the other one. It certainly didn’t look the innings of a professional cricketer, let alone an international one. But maybe he hadn’t been playing very much and was quite rusty, so took a while to find his rhythm. And that’s really Ed’s point, that rhythm, both when batting or bowling, can be at least as important as watching the ball.
There are some good reasons why players are told to concentrate on watching the ball, apart from the obvious one that you need to know where the ball is in order to hit it. One is that players can pre-meditate a shot. A slow bowler floats the ball in the air and the batsman is looking towards the pavilion, where he expects the ball to go, head up as he players his shot. Soon he finds himself back in that pavilion.

The other reason is that players can easily be full of distracting thoughts and nerves, and that telling them to watch the ball gives them something to concentrate on that’s both essential and can block out the other distractions.

At the start of the innings, or when facing a new bowler, there are a lot of variables for the batsman to deal with. Batting is all about anticipation, so it’s essential to watch the bowler’s action and the release of the ball. Focus then jumps to where the ball pitches, and the speed and bounce off the pitch need to be noted as each cricket pitches are quite variable.  It’s usually only once batsmen have been in for a while that they can accurately anticipate what the ball is going to do, and then get into a rhythm. At that point, they may say that they are “seeing it like a football”, which suggests that they are still concentrating on the ball. They are anticipating so effectively that the ball is exactly where they expect it to be at contact, and may even say they can see the maker’s name on the ball.

To bat effectively, you need both concentration and being relaxed in your movements. Some batsmen, and our “streaky” international may well be one of them, have great difficulty in getting relaxed  and may actually find that the instruction to concentrate on the ball keeps them tense. And you can’t make smooth movements when you’re tense. So for those players, whilst they still need to watch the ball, it may be better to give them a word or phrase that stops their body from freezing up, and allows their subconscious brain to carry out the well-practised task of playing shots without the conscious brain trying to take over.

So whilst I would maintain that watching the ball is still essential to batting, there is never going to be one coaching instruction that will be the best for everyone. And, in case you’re wondering who that former England player was, it was indeed Ed Smith.

David Donner

Friday, 17 October 2014

Sports Vision Casebook - Catching

I recently received a call from a lady whose 14-year old son plays in the school cricket team. She told me that his coach had noticed that he had difficulty with balls above eye level and thought he might have an eye problem.

I assumed from this that the problem was when he was batting, dealing with short-pitched deliveries. So when he came in for his appointment, and after establishing that he had no significant prescription, I asked him if he had problems dealing with bouncers. He replied that he had no problem, as he always ducked out of the way. He did, however, have some difficulty with balls that were angled into him. It turned out that the coach’s remark referred to trying to catch a ball that had been skied in the air.

I wasn’t sure whether this was a problem of technique or of being afraid of a hard ball, so I tried to come up with a strategy to cover both. I explained that it’s easy to lose confidence once you’ve dropped one or two catches, and you can start hoping the ball doesn’t come to you. This means that when another does come your way you are slow to get into position, and you are nervous, which makes your body stiff and the ball more likely to bounce out.

The important thing, therefore, is to build up confidence by starting with easy catches using a tennis ball, but with prefect technique. There are two ways of catching a high ball, and I think that optically the better of the two is the “reverse cup”, also known as the Australian method, in which the hands are reversed with the thumbs are interlinked. The advantage of this method is that you can watch the ball right into your hands, whereas that’s almost impossible with the “Orthodox” or English method (little fingers interlinked) when the ball is dropping past your face. Another advantage of the Australian method is that if the ball does bounce out, it’s easier to grab it again before it hits the ground. Some people actually manage to watch the path of the ball through the gap between their thumbs, which can give this method a third advantage.

People often talk about “soft hands”, but you don’t want them to be too soft and floppy. It’s more important that your shoulders aren’t tense, and shoulder tension is a major reason for the hands not “giving” when taking the catch.

The idea is to gradually increase the height of the ball which can be achieved by getting someone to hit it up with a tennis racket. Then you can move on to catching a cricket ball, again starting with lower heights.

When confident with catches that are straight to you, you can move on to catches for which you have to run. It’s essential that you look carefully at the point when the ball is at its maximum height, so your brain can tell (instinctively) when gravity will bring it down to a catching height. As you run to take the catch, the aim is to get in such a position that the ball looks as if it’s going in a straight line towards you, and not off to the side. It should also appear to be going at a steady speed: if it looks to be accelerating upwards, you need to move back; if it’s accelerating downwards, you need to me forwards.

When you do take a good catch, you need to take time to recall it in as much detail as possible, and to use this as part of your visualisation practice and match preparation. If he takes all this on board, our young cricketer should soon be hoping the batsman will sky a shot in his direction, anticipating and relishing the chance to impress the coach.

David Donner


Monday, 1 September 2014

Sport Vision Casebook: Eye dominance in golf

Much of my early work in sports vision was in golf. I was once part of a team that did some vision screening at a golf academy in Sussex. At that time I was still thinking like an optometrist, looking for eye problems that could be solved in a conventional way, for instance with contact lenses.

We found no problems with the eyes of nearly all the students. There was just one young man who’d always had a weak eye (if I remember rightly he had a small squint). His problem was reading the greens. Apparently, when he had another player read the greens for him, he’d won a tournament. It was only some time afterwards that I thought that if I had an expert telling where to aim, I still wouldn’t win any tournaments, but I’d play an awful lot better golf than normal. 

There’s no doubt that being monocular would be a disadvantage for professional golf. But at the risk of seeming harsh, I did wonder if this chap was starting to see lack of binocular vision as a reason for failure, rather than being determined not to let it hold him back.

Since then, my focus has shifted more to the “software” side of vision: in particular, how experts use their vision in sport. One “hardware” issue that often crops up in golf, however, is eye dominance. Over the years I’ve seen many golfers, from the very young to quite elderly, who feel their eyesight is letting them down when they’re putting. 
It’s always necessary to do a full eye examination to rule out problems with their prescription or eye health, but the next thing I do is to check their eye dominance. I get them to place their right hand over their left, leaving a little gap between their thumbs and forefingers. Standing a few feet away, I get them to raise their arms and to look at my nose through the hole they’ve made. It’s easy to see which eye they are using for alignment. I then get them to repeat the test, but with their left hand over their right. If there’s any hesitation or inconsistency, I get them to do this a few times. 

I then put a golf ball in front of them and get them to set up in their normal putting stance. I put another ball on the floor about twenty feet away. I ask them to put their hands together, roughly as if they were holding a club, but in such as way as again to leave a small gap they can look through. I ask them to line up with the contact point on the ball. If they close each eye in turn they can tell which the aligning eye is. I then ask them to play an imaginary shot to the other ball, and again see which eye is aligning. 

I’ve found on a number of occasions that they are aligning with different eyes for different parts of the stroke, and I believe that this can cause their shot to stray slightly off target. If they’ve shown consistent eye dominance in the first assessment, I try and get them to use that eye all the way through their putting. It usually just requires a small change in head position to achieve this, and people report greater putting consistency as a result.

If you have a sporting problem you think might be vision-related, you can email me at

Monday, 4 August 2014

Culture of Success

I recently came across an interesting quote: “Culture eats strategy for breakfast”. The quote has been attributed to Peter Drucker, a management consultant, but I am far from the first to see its relevance to sport.

The idea is that if you want to build lasting success, just changing a part of the set-up is unlikely to bring that about: you have to establish the right culture that permeates through to every part of the organisation.

There are two parts to bringing this about. Firstly, there’s a dream (a sports vision, if you like); then there’s getting everyone else to buy into that dream. It’s the second part that’s usually the most difficult. So the club owner should have a vision of where they want the club to be, and get the coaches to work towards that end.

A major part of creating a culture of success is to establish some core values, which will be the basis of that success. The US secret service, for instance, has 5 core values: justice, courage, duty, honesty and loyalty. Rugby coach Eddie Jones has three core values: respect (for team mates, fans, game and referee), discipline (doing things in the right way at all times) and courage (both physical and mental).

Coaches need to exemplify these values themselves, as well as reinforcing them to their players by rewarding good behaviour and punishing bad behaviour, mostly by making them factors in selection.
Of course these values need to be realistic, which depends on the level and personal circumstances of your players. Successful teams also usually have a range of personalities: especially useful are those who may not appear to be the most talented, but seem to bring out the best in others. A prime example of this is the “Butler Way” – the philosophy of the Butler University “Bulldog” teams (especially basketball) that was established nearly 100 years ago. Their key is to find players who not only fit into the culture of the organisation, but are driven to achieve success through inspiring their team mates. As they take to the court, they see the word “catalyst” to remind themselves of the chain reaction that will lead to victory. In the past decade alone, Butler teams have captured 26 conference championships in four different leagues. That’s a culture of success. 

David Donner

Thursday, 24 July 2014


I was recently listening to a cricket podcast. The expert panel was asked about the benefits of vision training, especially for late developers. The experts agreed that generalised vision training was of little use, except possibly as a psychological boost. Vision training that was done in the context of the sport, however, might be helpful. Needless to say, those views echo my own precisely.

One coach said that it could be useful to patch one eye when practising bowling, batting or fielding. He has got his batsmen on occasion to wear a patch over what he called the “motor eye”, which is the eye that leads when we are tracking a moving object. The idea was that this would “strengthen” the other eye. I think he was on stronger ground when he suggested that because this was putting his batsmen in a challenging position, so it would help them deal with other difficult situations that they might encounter in a match, which is why his players found it both challenging and useful. I’m certainly all for making practice highly demanding, so that you are mentally and physically prepared for the challenged that will come your way on match day.
I was reminded of an experiment on eye dominance and tennis that I’ve discussed before. It was found that blurring the non-dominant eye of elite tennis players had a deleterious effect on performance, whereas fogging the dominant eye did not. This rather paradoxical finding was explained by suggesting that the non-dominant eye was essential for depth perception. Whilst this may well be true, I’m no longer sure that it explains the findings as the dominant eye must also be essential for really accurate depth perception.
I therefore suspect that what happened in these tennis players was the same as happened to the cricketers: when the dominant eye was blurred, it felt really strange, so the players had to concentrate harder on the ball. In doing so, they were able to perceive monocular cues such as image size, which meant that their depth perception wasn’t actually too badly affected. When the non-dominant eye was blurred, however, because the effect on vision was less noticeable, they made little or no adjustment for it.
So, patching the dominant eye can be a useful exercise, but it probably needs to be used sparingly. It’s likely to result in adjustments to the body, such as a head tilt. If a player doesn’t have really strong eye dominance, they could start switching during competition, and if they don’t make the necessary compensatory adjustments their timing and other judgements could be all wrong.
I’m not sure how this relates to late developers, but I suspect it depends on why they are developing late. It could help with getting them to concentrate on the ball as it leaves the bowler’s hand, or help them get into line better. But if they are late developers because they haven’t played much cricket, you would probably be better leaving them to work this out for themselves. If the idea is to make the practice more challenging, there are other ways of doing this, such as using smaller balls and/or bats, or getting them to read markings on the ball as it approaches.
Patching can be useful in a number of sports. In golf, for instance, it could be used to ensure that the player maintains eye dominance when switching from the ball to the target. In rugby, you might notice that some players are not paying enough attention to the passer’s hands as he passes the ball. This means that they are late in reacting to the ball as it appears in front of them and therefore drop it. One solution would be to patch the left eye for passes coming from their left, and the right eye for passes coming from their right. This would then require them to turn their head towards the passer so they pick up the flight of the ball at the earliest stage. I would probably still be inclined to achieve a similar effect by using smaller balls, balls of a dull colour that are harder to see, or balls with numbers or letters on that the players have to read out before they catch them.
Patching both eyes, otherwise known as blindfolding, certainly has a place for enhancing kinaesthetic feedback. But that’s for another day.

David Donner

Tuesday, 15 July 2014

The Chimp Paradox

I’ve talked a lot about the conscious and subconscious parts of the brain, but there’s another part known as the limbic system. I tend to think of this as an alarm system: all sensory information goes to this part of the brain first and is scanned for potential dangers.

This system was great when our ancestors were living in the jungle and could be eaten by a predator at any moment, but can cause problems in our modern lives. So an opening batsman preparing to face a fast bowler will have made a conscious decision to play cricket that day. The precise movements required to play a shot at the right time to hit the ball successfully depends on the subconscious brain. But as the batsman watches the fast bowler marking their run-up, the limbic system may well be sending out alarm messages, such as “He looks big; the ball’s likely to be coming at me very fast; I didn’t do very well when I played here last time”.

In his book “The Chimp Paradox”, Dr Steve Peters refers to this limbic system as “The Inner Chimp”. As Dr Peters acknowledges, it may not be anatomically or philosophically correct to describe the inner chimp as a separate entity from the “human” brain. But it seems to be an incredibly powerful and useful way of thinking about it. The book also has chapters on achieving success, confidence and happiness, so it really could change your life.

If you find that you have over-reacted to a situation with an emotional response that you later regret, you can blame it on your inner chimp. But it’s like having a pet dog: although you aren’t your dog, you are still responsible for how your dog behaves. So you have to be able to control your inner chimp as you’re responsible for it.

It probably won’t work if you just try and ignore your chimp. You can manage it, however, by setting up default behaviours such as pre-shot rituals in sports such as tennis or golf which enable you to carry out the task before the chimp starts acting up.
Recent examples of sportsmen whose chimps seem to be out of control include Andy Murray and Luis Suarez. Of course, since Dr Peters has worked with Suarez, he’s not exactly the best advert when he carries on biting players.

In the end, though, the player has to decide to help himself. Unfortunately, in the case of Suarez, he decided to help himself to a piece of Chiellini’s shoulder.

David Donner

Tuesday, 8 July 2014

Adam Gilchrist vs Shaun Tait | Access All Areas

This is great footage of Adam Gilchrist facing Shaun Tait at Lords last Saturday. Wearing a GoPro camera on his helmet shows great insight to his vision and movement to enable him to hit 2 boundaries!

Friday, 27 June 2014

World Cup 2014

One good thing about England’s early exit from the World Cup is that we won’t have to endure seeing them lose on penalties. It’s typical that the one time we employ a psychiatrist to help with this, the team gets knocked out in the group stage before a penalty shoot-out becomes possible. It’s probably just as well as the players’ negative attitude to the penalty shoot-out seems to run pretty deep. I was listening to Rio Ferdinand the other day saying that he didn’t think that Dr Peters’ success in sports such as cycling was particularly relevant to taking a penalty in a major tournament. Leaving aside Dr Peters’ successful work with Liverpool FC this season, Ferdinand said “I don’t think one person can have that much of an effect on people; he can ease people’s nerves maybe a little bit and make them feel more confident. But when it comes down to that moment of going up there and taking a penalty, things change”. He went on to say: “It’s one, single split second….you’re in the middle of that pitch, all alone in a massive goldfish bowl, being watched by millions; and that pressure is all steeped on your shoulders in that one moment…it’s difficult…when you walk out there and you’ve got those fans there, it’s different (from practice)." Ferdinand described his own experience of preparing to take a penalty in the Champions’ League Final in 2008: “I was next in line after Gigsy. I couldn’t even concentrate on Gigsy taking it: my legs had gone”. Fortunately for Manchester United, Ferdinand didn’t actually have to take the penalty. I can’t think of a better description of why you should have a psychiatrist or psychologist working with the players to prepare them for the moment when they are likely to be under the most pressure of their lives. One person who did take a penalty for Manchester United that day was Owen Hargreaves, who went after Christiano Ronaldo, who had just missed with his attempt. Hargreaves had practised penalties with a lot of the Chelsea players, such as John Terry, when playing in the World Cup with England. They had seen him go the same way, every day: top left. Michael Ballack had also seen Hargreaves practise penalties with Bayern Munich. “I practised every day; I hadn’t missed for a month; top left. As I went up to the penalty spot, I guessed the Chelsea players were pointing where I was going to go. I thought that might happen. So when I went up there I thought “Why not just put it in the other corner on the bottom”. And as I went up I thought “Christ, that goal looks really small”. I’m going to do what I know best, and see if he can save…if my best is better than your best. And I smashed it top corner and it went in”. It seems you have to have been brought up in Germany to be able to clear your head and concentrate on the task in hand: decide where you are going to aim for; focus on that point in the goal; focus on the ball; shoot. The psychological problems of playing for England seem to run pretty deep. This is Steven Gerrard talking before the Uruguay game: “Basically, to realise it could be a terrible, long, frustrating summer if we don’t get it right on Thursday,” Gerrard recalled. “There is no hiding place for a player when you go out of a tournament earlier than you expect. It can be tough and it can take an awful long time to get over it. A lot of people know that in the dressing room but there are a few young lads in there too, so it was important for them to realise what is at stake and how important this game is. “I have been there. I have had that feeling. So I know what that feeling is about and that is the feeling I don’t want on Friday morning. It wasn’t a message to scare any of the lads but it was a wake-up call to everyone in the room. It wasn’t to scare anyone, or intimidate anyone, but this is the reality of where we are and we need everyone focused and right on it, individually and collectively, on Thursday, otherwise it is going to be a terrible, long summer.” I somehow doubt that Dr Peters (about whom more in due course) advised the England captain to dwell on the consequences of losing a match on the eve of playing it. That might, however, be at least a partial explanation for how Gerrard and the team played. David Donner

Wednesday, 11 June 2014

The A - Z of Sports Vision - The Zone

Some athletes, when they are performing at their peak, appear to be in a world of their own. Nick Faldo, talking about his Open win at Muirfield in 1987 said “Two steps in front of me was my only focal point. The rest was a blur, partly due to the weather and partly because I was completely engrossed”. Tony Jacklin refers to it as being in a cocoon of concentration: “I’m absolutely engaged, involved in what I’m doing at that particular moment”. We now refer to this state as “The Zone”, or “flow”. When a state of flow is reached, a number of chemicals are released in the brain. One of them is a pain-suppressor, Anandamide, which shares similar properties to THC, the active ingredient of Marijuana. Other drugs that are released include amphetamines such as dopamine, endorphins (the name is derived from endogenous morphine), and serotonin, the mood-changing drug that’s released when people take Ecstasy. No wonder athletes talk of “runners’ high”. Getting into the zone requires your subconscious brain to take over control from your conscious brain. This rules out most beginners, as when you are learning a new activity, it’s likely that you are consciously thinking about what you are trying to do. But once you’ve reached the standard of an expert, the main task is to keep conscious thoughts out of it. So if you really try and get in the zone, the chances are you won’t achieve it. The very nature of it requires you not to be trying, not thinking consciously about what you’re doing. Music can help to achieve this state as can visualisation. But another way is to concentrate on your vision – supplying your subconscious brain with the visual information it requires to make the best decisions. Billy Jean King described her experience of the zone as follows: “I concentrate only on the ball in relation to the face of my racket, which is a full time job anyway, since no two balls ever come over the net the same way”. And that seems as good a way as any to end this A to Z of sports vision: I hope you’ve found them of some use or at least interest. I intend to keep blogging. My next one will be a review of a book that could change your life…… David Donner

Monday, 12 May 2014

The A - Z of Sports Vision - Yips

Most people associate the yips with golf. Typically, a player lines up a short putt but, instead of an easy tap in, the player seems to jab at the ball, sending it wide of the hole. In other sports, the condition can become so extreme that the movement becomes completely impossible, such as a darts player who can’t release the dart, or a spin bowler who can’t release the ball. The cause is not fully understood. One theory is that is caused by an excess of fine muscle activity (focal dystonia), but there seems to be a lot more to it than that. For a start, the prevalence of focal dystonia in the general population is about 3% (Nutt et al 1988), whereas nearly 50% of golfers are said to suffer from the yips to some extent (Smith, Malo et al, 2000).
So there would appear to be a significant psychological element to the yips. In golf, for instance, the yips often disappears if the ball is hidden under a cover and the golfer doesn’t know if there is always a ball to be hit or not. It can also disappear if the ball is fixed to the ground, the hole is removed, or is replaced by a symbolic target like a tee (Marquardt 2009). Often the yips are only apparent for putts of a particular length, and if the putt is longer or shorter than this there is no problem. All this suggests that the problem is not essentially a physical one; otherwise it would still be present in all these other situations, not just in certain situations. Anxiety about the result may well be at the core of the yips, which explains why they are more likely to occur over a short putt, when missing it would be interpreted as a failure, and not for longer putts which have lower expectations of success. As the golfer becomes aware of the problem, the conscious brain starts to interfere with process. This makes the action jerkier and less likely to be successful, so a viscous circle develops as the stress levels rise with each unsuccessful action. There are various psychological methods of dealing with the stress element of the yips; visualisation and self-talk are often useful. One golfer had problems initiating his down-swing. The cure was to get him to say a three-syllable word (“Edelweiss”) to match the timing or rhythm of his swing. So he said Ed-el-weiss to correspond to the initiation of his backswing, the top of his back-swing and the point of contact with the ball (Beilock 2010). But for many a simple treatment is to take them back to when they can swing the club smoothly. This may be achieved by getting them to close their eyes when they strike the ball, or swinging the club without a ball. You then gradually reintroduce the difficulty whilst maintaining the essential visual elements, such the Quiet Eye focus on the ball. This should help keep the conscious brain from interfering. And if things break down again, you retrace the steps (hopefully not right back to the start) and build up again. David Donner

Tuesday, 29 April 2014

The A - Z of Sports Vision - X-Axis

I read quite a few scientific papers (so you don’t have to), but I despaired of finding anything X-related until I came across a paper by Rienhof et al published in “Frontiers in Psychology” last year.
The authors wanted to see if the perceptual skills required for expertise in one sport could be transferred to another sport. I’ve talked about the “Quiet Eye” a few times. In basketball, for instance, experts have a longer Quiet Eye period, where they fixate a precise target such as a particular part of the rim, than lesser players. The authors of this paper wanted to see if that advantage would be transferred if elite basketball players took up a new sport that also involved throwing, such as darts. They suggest that free throw misses may be more likely to be due to horizontal errors than vertical ones (I actually don’t see why that should be true, but never mind for now). Given that in both darts and basketball you’re throwing towards a target that’s straight in front of you, but at different heights, they said that differences between the free throw task and the darts task might be greater in the y-axis (vertical) than in the x-axis (horizontal). They therefore speculated that expert basketball players would be more accurate in the horizontal plane when throwing darts, but no more accurate in the vertically. They found that skilled basketball players were more accurate at throwing darts (none of them had thrown darts before). Furthermore, they found that the skilled players did indeed show significantly smaller deviations on the x-axis, but the y-axis deviation was similar for both groups. They didn’t find, however, any differences in the Quiet Eye period between the two groups when playing darts. This suggests that either the Quiet Eye is specific to a particular task, or that it is only displayed once the skill has to some degree been learnt. It seems logical to me that if you’ve achieved a high level of expertise at one throwing task, you will to some extent be able to transfer that to another throwing task. It could take a while however to work out the precise visual cues required to become an expert at the new sport. Give time, I suspect that the expert basketball players would work it out before the lesser players did. David Donner

Monday, 31 March 2014

The A - Z of Sports Vision - Watch The Ball

In the recent 6 Nations rugby there were some classic examples of players knocking the ball on because they had taken their eyes off the ball, usually because they are distracted by a player about to tackle them. But then in football, players are often accused of “ball watching”, when they are so concentrated on the ball that they don’t notice that a player has been left unmarked.
But if that’s confusing, you would think that the requirement to watch the ball in sports such as tennis or cricket would be sacrosanct. However, numerous studies have shown that this isn’t exactly the case: the ball is actually travelling too fast to do this. One of the first was Land & Mcleod (2000) who found that elite batsmen followed the ball for a while before switching their vision to where they predicted the ball would bounce, and then tracking the ball from there until they hit the ball with their bat. Some batsmen, however, are more elite than others. A recent study (Mann, Spratford & Abernethy, 2013) studied two batsmen who had played more than 70 Tests matches, averaging over 45 (I suspect one of them might have been Matthew Hayden), as well as two club-level cricketers. They batted against a ball-projection machine that displayed a life-sized video projection of a bowler in his run up. At the moment of ball release a ball was actually released through a hole in the screen. The participants wore an eye-tracking device that the direction of the head and gaze when batting. They found that the elite batsmen tended to keep their gaze either in alignment with, or ahead of the ball. In contrast, the club batsmen were more likely to have their gaze either in alignment with or behind the ball. The latter only had their gaze ahead of the ball for short-pitched deliveries, and only then for a short period of time after the ball had bounced and before they made contact with the bat. On average the elite batsmen directed their gaze further ahead of the ball, and for a longer time, than the club players. In particular, elite players directed their gaze ahead of the ball immediately prior to hitting it with their bat, whereas club players tended to be behind the ball at this crucial time. Elite batsmen were found to couple their head movement more closely to the movement of the ball, especially as it got nearer to them. They also moved their gaze further in advance of their head direction. In other words, the elite batsmen closely aligned their head with the direction of the ball, whereas club-level batsmen more closely aligned their eyes with the ball. Sometimes the elite batsmen would have their gaze so far in advance of the ball that the image of the ball would be in their peripheral vision; but they still managed to keep their head aligned with the ball. The authors liken this to using a miner’s torch on your head to keep a spotlight on a moving object. Whereas Land & McLeod had found that better players made one saccade (where the eyes jump to a new location) to where they expected the ball to bounce, and then tracked the ball to contact, these elite players made a second saccade after the bounce of the ball to where they anticipated the contact would be. This second saccade was made for balls that were either short of a length or on a good length. Club players were much less likely to make a second saccade. All players made just one saccade when the ball was of a full length, but the elite players’ saccade took them past the bounce point to the predicted contact point, whereas that of the club players tended to lag behind the contact point. The coupling of the head to the movement of the ball seems to help the elite batsmen predict where the contact point will be. Crucially, this meant that the elite players were more likely to have a sharp focus on the contact between bat and ball compared with the club players. “Keep your head aligned with the ball” would not be a particularly helpful instruction to aspiring young batsmen, even though it seems to be what’s required at an elite level. I think the best coaches could advise would be to watch the bowler’s action carefully (so you can predict where the ball will bounce and what type of delivery it will be), carefully note where the ball pitches, and try and watch the contact point between bat and ball. David Donner

Monday, 3 March 2014

The A - Z of Sports Vision - Visualisation (and video)

Visualisation should be an essential part of any athlete’s training because it can have a profound effect on performance. In fact, most athletes probably do use visualisation, but they don’t necessarily use it very effectively, and may even be using it in a way that negatively affects their performance. For instance, if you replay a mistake you’ve made over and over in your head, it’s like practicing making errors so makes it more likely that you’ll make the same mistake again. The first mistake people make is to think that visualisation is just about vision – what you’ve seen. That’s partly because visualisation is something of a misnomer: “mental rehearsal” would be a better term (except I’d have to come up with another “V”) because it allows you to use all your senses to recreate the activity, and that’s when it becomes really powerful. To give you an idea just how powerful it can be, 10 volunteers took part in mental workouts 5 times a week for 12 weeks in which they had to imagine pushing against a heavy object (Ranganathan et al, 2003). They actually increased their bicep muscle strength by 13.5%, and maintained this increase for three months after the training stopped. A famous imagery experiment involved wiring electrodes to the legs of an Alpine skier to test out the notion that vivid imagery produces electrical activity within the muscles similar to the electrical impulses produced during actual movement (Suinn 1980). The experiment showed that when the skier was sitting down, simply thinking of skiing downhill, similar electrical patterns were found in the muscles as if he had actually been skiing. By imaging or visualising yourself playing sport, the muscles you would use to physically perform the task are stimulated at a very low level. This gentle muscle activation is not strong enough to produce actual movements, but it establishes a blueprint for that particular movement or situation. By visualising a successful performance, it makes it more likely that you will produce the correct response while under pressure. The subconscious brain can’t easily distinguish the difference between imagination and reality the way your conscious brain does. This is why dreams can sometimes feel really lifelike. So visualisation is just another form of practice, and it’s much better to practise doing things well than doing them badly. Visualisation can be used for learning new skills, strategies and routines, but it can also be used to motivate, control stress and boost confidence. It can be used to improve concentration and to recover from injury, as well as dealing with errors and stressful situations. It’s also been found that athletes instructed to imagine successfully performing a task voluntarily practised longer than others. You can visualise your performance as you normally see it, or as it might look on TV. Video can help athletes visualise their performance in real time. I’m currently videoing some rugby players in training. The idea is to pick out some of their best bits, and maybe set them to music, so players can use this as part of their pre-match preparation and general confidence booster. It will be interesting to see how it works. David Donner

Tuesday, 4 February 2014

The A - Z of Sports Vision - Umpires

I was recently one of the tutors on a course for aspiring cricket umpires. There was a discussion about where the bowler’s end umpire should stand so that he can see the bowler’s feet land (making sure it’s not a No Ball) as well as the flight of the ball.
They were given the standard advice that they should keep their head still and flick their eyes down to see the landing of the feet, and then flick them up to watch the ball and where it pitches so they can adjudicate for LBW and other decisions. It was assumed that I, as an optometrist, would back this up. It was a little awkward when I had to say that conventional wisdom was actually wrong. It is true that batsmen, for instance, should keep their head still at the moment of contact. You’ll see many batsmen lift their head when they go for a big shot and either miss the ball or sky it into the air. I used to think that this was due to over-anticipation of where the ball was going to go, or just some kind of “red mist”. But I’ve now come round to the idea that it’s our old friend balance. If you’re moving forward and you’re not well balanced, you’re likely to fall flat on your face. In order to prevent this, your brain brings your head up so that your centre of gravity moves backwards. You don’t execute the task very well but at least you don’t fall over. If your rugby scrum half is firing the ball over the fly half’s head, it’s for the same reason. Anyway, I digress. None of this means that keeping your head still is the best way to track a moving object. Hold a finger in front of you and move it slowly from side to side. Follow your finger with your eyes only, keeping your head still. Gradually increase the speed of your finger. You’ll very soon find that you’re losing focus. Now try again, this time moving your head and eyes together. You’ll probably start to get dizzy before you lose focus on your finger. It’s one of those lovely examples when conventional wisdom – everything you thought was right – turns out to be wrong. David Donner

Friday, 3 January 2014

The A - Z of Sports Vision - Tau

Hofsten (1983) videotaped infants between 34 and 36 weeks as they reached out towards a brightly-coloured object travelling in a circle. In 144 reaches, they only missed 17 times, and the mean timing error was just 4.4ms when the object travelled at 45cm/second. McLeod, McLaughlin & Nimmo-Smith (1986) asked non-games players to hit vertically-dropping squash balls towards a target with a bat. They were extraordinarily consistent, with standard deviations of just 10ms in 90% of trials, and only 5ms in 50% of trials. So “ordinary people” can demonstrate fine timing even without any particular practice. How do we manage these extraordinary calculations? The answer is that we don’t calculate them. Suppose you are a fielding on the boundary in cricket and the ball has been hit in the air towards you. To calculate the balls arrival (Time-to-Contact or Tc), you’d have to estimate the distance the ball has to travel and its speed, and then divide one by the other. This doesn’t seem a likely method for adults, let alone infants. Lee (1976) proposed that the time to contact could be assessed by using changes to the size of the image that an object creates on retina as it approaches. For our fielder in the deep, the ball approaches him at a fairly constant speed. But when it’s far away, the size of image it forms on the retina doesn’t change much. As it gets nearer, however, the image size gets larger at an increasing rate. The ratio between the image size and the rate of expansion of that image size is known as tau (it’s actually the ratio of visual angle of rate of change of visual angle, but you get the idea). Tau can be used to predict the time at which an object travelling at a constant speed will reach us, and therefore the time at which we need to instigate a movement to intercept it. In a brilliant experiment, Savelsbergh et al (1991) got subjects to catch a ball one-handed. But the ball actually consisted of a small ball 5.5cm in diameter surrounded by an inflatable balloon 7.5cm in diameter. As the balloon approached the catcher it was mechanically deflated without he catcher’s knowledge, so by the time it reached the catcher’s hand it was the same diameter as the small ball. The ball was travelling at a constant velocity, so if the catchers were using that velocity to judge when the ball would arrive, they should still catch it. But because the ball was deflating, the ball’s image on the retina did not expand at the expected rate, so the catchers were late in their attempts to intercept the ball. This proved that the catchers were using tau when catching. Of course for the fielder on the boundary the ball isn’t coming in a straight line, it’s in a parabola, and the fielder may well have to run laterally to get to it. There are other visual strategies that can be used for successful catching, but that’s for another blog. David Donner