Ofcourse one part of the equation is speed. The faster you throw a ball, the harder it is to stop. If we take the numbers in the above mentioned article for granted, we would need a throw in which the ball takes less than 0.25 seconds so the goalkeeper can't react or just barely. If our throw takes longer the goalkeeper will see the ball coming and the chance of stopping it will increase. So the next thing we need to know is how hard we can throw. I don't know of any numbers for the canoepolo throw, but I found this article article about elite male water polo players. The throwing speeds varied between 21.0 and 29.8 m/s, with an average of 25.3 m/s. Now we have this average we can look within what distance we want to throw. From the point of release to the goal the ball will cover 6.3 meters in 0.25 seconds. Taking the point of release at 1 meter so the ball has to travel 1.5 meter upwards on average, the distance from the goalkeeper we need is 6.11 meters to be within his reaction time. Keep in mind this is for ELITE water polo players, these guys throw hard. If you don't have a feeling for what 25.3 m/s, it's about 91 km/h. Is your throw let's say 15 m/s (54 km/h), the distance you want to be within shrinks to 3.4 meters. That's not even taking into account some goalkeepers may react faster.
So how is it possible we can still stop a ball although the travel time of the ball takes less than our reaction time? That's where things get interesting and we get to the second part of the equation.
Something we all do, most of the time unconsciously, is predicting what someone else might do or what might happen. When you walk through a crowded street you don't bump into people or at least I hope you don't. We look at each other and predict what the other person might do based on their previous movement, where they're looking, their body positioning etc. The same thing happens in sports. We look at our opponent and try to predict what he/she might do. The better you are at this, the sooner you can react. In some sports players/coaches scout their opponents before a match and try to find out which tendencies they have so they can react on things before they happen, winning valuable time for themselves. There are also quite a lot of researcher busy to find out what makes a person good at predicting what someone might do, for example what goalkeepers look at before stopping penalties in football. For this example it was found that the better goalkeepers tend to have similar gazing behavior and there are training programs to improve this behavior.
This has some implications for the way we train and play the game.
- The obvious one is don't try to throw at goal from 6+ meters too often with a good goalkeeper at goal, he will even have time to react when he didn't see you throw.
- For goalkeepers a part of their training should be trying to predict shots. This can be useful for players for intercepting passes as well.
- Try to camouflage your throw. If someone can't predict where you're throwing, they can't react as fast.
An example of an exercise that incorporates this and can be used in a warm up is as follows: Player A has the ball with player B across of him. Player C starts to paddle from player B towards player A. Player A has to pass the ball in an almost straight line to player B before player C reaches him while player C also tries to intercept the pass. When the pass is made player A starts to paddle towards player B and the same as above happens again.
Of course there are a lot of exercises that can be used. Just shooting at goal is another way to do it.
The team I coach has their first tournament of the year tomorrow. As it's a developing team I've given them the instruction to try to only throw the ball from within 3 meters of the opponents goalkeeper and only from further away when there isn't a goalkeeper. This instruction is for two reasons. One is limiting the time the goalkeeper has. Second is they need to learn to create opportunities, by adding this constraint I hope they'll start thinking how to open up the opponent's defense and become more patient in attack. We'll see how it goes!
If you have anything to add, have questions or don't agree with something written here don't hesitate to respond. I love to hear your ideas, training methods and feedback.