How do you catch a cricket ball?

Did you ever think about how a fielder in a cricket match manages to catch the ball?  Probably not.  But think about it.  The batsman hits the ball and it travels in an arc, and probably across the line of vision of the fielder.  Furthermore, its path will be affected if the ball is spinning and the wind is blowing. 

How does the fielder know what to do?

A physicist or a mathematician would need to work out the forces acting on the ball, how fast the fielder can move in order to work out where the fielder will meet the ball.  All of which are extremely complex and impossible to calculate in the time available.

So how is it done?  Well it is much simpler than the physicist’s method.  Basically, the fielder runs in the direction which minimises the apparent movement of the ball relative to him.  And if he continues to do that, the ball and he will arrive at the same place at the same time. 

The fielder solves the problem by using a heuristic process, essentially a ‘rule of thumb’, a shortcut that works for very specific problems.  Heuristics are very practical, we use them all the time because they are quick and make problem solving much easier.  

Unfortunately, because we use them so often, we get out of the habit of thinking originally, we make the same assumptions and use the same old ways to solve problems.  For this reason it is important that we identify the assumptions relating to a difficult problem and the thinking (or not) that goes with them.