Dylan Martinez/ReutersAsamoah Gyan’s successful penalty kick down the center.
Our latest Freakonomics Radio podcast discussed the fact that soccer players are generally reluctant to aim penalty kicks at the center of the goal even though the data show that is the most effective spot.
We expanded on this topic in a (U.K.) Times article yesterday.
And then Asamoah Gyan of Ghana went out and made us look smart in a match against Serbia. In the 84th minute of a nil-nil game, Gyan took a penalty and went center with it, producing a big 1-0 upset. (As of this writing, Gyan’s was the only penalty kick taken in the World Cup, although there will be plenty in the knockout round, when tie games are decided by shootouts.)
The method is effective because keepers usually commit to jumping left or right on penalty kicks just as the ball is struck. Kicking to the center seems to work with English keeper Robert Green as well, but for different reasons.
(Hat tip: Collin Campbell.)
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you should roll your dice twice: once to decide which way to go and once tot ell the goalkeeper which way you are going to kick it – nothing like a little bit of mind games….
@3 You still have to consider the odds of actually hitting ‘upper 90.’ If it were so easy to hit, professional footballers would just do that every time. But, as we know empirically, knockout round games don’t go forever with each teams’ players perfectly placing the ball into the top corner of the goal. So game theory does apply here. Which part of the goal offers you the most reward with the least failure?
Another factor often forgotten in connection with the on-center PK issue deals with end of overtime PKs. That has to do with the “tired legs” syndrome after participants have already spent regulation time +overtime periods on the field.
I am surprised more coaches don’t encourage their leg-warn players to kick on-center and take max advantage of the variance from the intended perfect placement the fatigue factor will create. Many more miss-struck kicks might become winners.
What everybody should stop doing is kicking Robert Green. It’s just one data point, but everybody already makes conclusions. Seriously, people, give him a break.
More to the point, penalty kicks are obviously a situation that calls for a mixed strategy. Always hitting 90 would work in a world without emotions, but in reality players face so much pressure that even the best of them occasionally miss. Think Roberto Baggio in the final game in 1994, just one of the many examples.
@ Zach/Nikki
That is why you aim for about 7/8 to the side of the net and put alot of pace on it. The best keepers in the world will probably get some hand on it, but the best strikers should be able to hit it hard enough for that to not matter.
Even a decent High Schooler can kick a PK hard enough for a correct guess to be totally irrelevant. Unless you both go middle, which makes for the easiest stop.
I would make a graphic of what I’m trying to say, but that seems frivolous.
Been kinda mentioned above, but I imagine the rare case of kicking middle and the goalie correctly staying middle is a pretty humiliating miss. Contrast that to a dive-stopped PK on the side or a miss wide, where you were either a bit too aggressive or the goal keeper made a great play, and a miss down the middle looks pretty pathetic.
That said… imagine if the guy from Ghana gets another PK and shoots down the middle again and scores. Goalies across the tournament will remember that (I’m sure they’re already thinking about it with the one kick). Will they hesitate a bit before jumping on the next PK? Does this open up opportunity for a side shot? Perhaps there is an option that one’s sixth penalty kick earns a slower side-reaction from a goalkeeper if 2 of the previous 5 PKs were down the middle.
Gyan definitely hesitated in his run-up to see if the keeper was going to commit. When he committed, the down-the-middle strategy was a no-brainer. Before the hesitation, maybe not so.
I like everything about this and the (U.K.) Times article, but I am a little sketchy on a particular detail in the (U.K.) Times article. I am looking into the penalty kick problem myself. However, whenever I solve for the mixed strategy Nash Equilibrium, I find that the kicker should be going to his weaker side more often than his strong side. I was wondering how you obtained your (contrary) result.