Dear WSC
I write to you concerning Simon Creasey’s fascinating article Parting Shots (WSC 259), in which Ignacio Palacios-Huerta of the London School of Economics describes that, in penalty shootouts, the team that taking a penalty first wins 60.5 per cent of the time. He then goes on to say that the team kicking first “has a 21 per cent greater probability of winning the shootout”. I don’t cast doubt on Mr Palacios-Huerta’s abilities as a statistician, but it is possible that he meant 21 per cent more probability of winning. If Team X has a 60.5 per cent probability of winning, then Team Y therefore has a 39.5 per cent probability. Team X’s probability is [(((60.5 / 39.5) -1) x 100) =] 53 per cent greater than Team Y’s of winning the shootout. Or, in other words, that Team X wins 21 per cent more matches means that their chances are 53 per cent better than Team Y’s for any given shootout. We can be sure that this is precisely what was going through Rio Ferdinand’s head after extra time in Moscow.
Patrick Finch, Eskilstuna, Sweden
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