It is always easy to criticise in hindsight. But last night’s goal kick or line-out decision in ENG v WAL got us thinking (and we do not claim to have perfect answers).
Ever faced the following situation? What you get from something depends on what another person does (their strategy / action); in turn, what they get depends on what you do (your strategy / action). In a sense what you both get is interdependent. These type of situations are commonplace in life, and in sports. They are strategic situations – a best response to a best response.
Well think of England’s decision to opt for a 5 metre line-out instead of opting to take a kick at goal last night. The payoff to England depended on their strategy and Wales’s response to that strategy (ok they could only watch a kick). England made a decision: go for the five points. Sounds like a strategic situation?
If you follow this reasoning, you might enjoy a branch of mathematics / decision science known as Game Theory – that helps understand strategic situations. If you think this is outlandish, think of the movie ‘A Beautiful Mind’ that immortalised Nobel prize winner John Nash (recently deceased report here). The central idea of a Nash Equilibrium is very simple: in a strategic situation, a rational decision maker will try to do the best he / she can, given that someone else is doing the best they can.
From post-match comments , England seem to have reasoned that their probability of kick success was lower than their probability of scoring a try. But it is clear from the Welsh comments post-game, that based on past-experience, they had prepared for an English throw to the front of the line-out (and so responded with a collective counter-press).
Should England have known that Wales would have responded like this? Well maybe, there was history. So this was not a just one shot game, it was a repeated game.
In summary, game theory helps us understand sports.
Let us know on @empiricalrugby1 if you would like more on this.