Wednesday, July 09, 2014

Loss aversion in penalty shootouts

From the BBC


















So you're much more likely to score when you're shooting to win, rather than scoring to avoid going out.

Kahneman discusses this phenomenon in his book Thinking Fast and Slow in the context of golf, where loss aversion actually improves performance:

"Failing to make par is a loss, but missing a birdies putt is a foregone gain, not a loss. [Devin] Pope and [Maurice] Schweitzer reasoned from loss aversion that players would try a little harder when putting for par (to avoid a bogey) than when putting for a birdie. They analyzed more than 2.5 million putts in exquisite detail to test that prediction. They were right. Whether the putt was easy or hard, at every distance from the hole, the players were more successful when putting for par [i.e. avoiding a loss] than for a birdie [i.e. achieving a gain]. The difference in their rate of success when going for par (to avoid a bogey) or for a birdie was 3.6%. 

This difference is not trivial. Tiger Woods was one of the "participants" in their study. If in his best years Tiger Woods had managed to putt as well for birdies as he did for par, his average tournament score would have improved by one stroke and his earnings by almost $1 million per season."

Why the discrepancy? Any sports psychologists in the house?

8 comments:

David Madden said...

Interesting. I would suggest its something to do with the nature of the contest/competition. A penalty shootout is head-to-head. Score and you win and eliminate your opponent. Make a birdie putt and you increase your chances of winning, but do not definitively win the contest. A better comparison might be between putts to win or tie a golf tournament, regardless of whether they were for birdie or par.
I think I read/heard somewhere that most penalty shootouts are won by the team going first - since this is determined by chance rather than skill it suggests that pressure has real effects on penalty taking, since when you get to the 4th penalty (sudden death) there is greater pressure on the team shooting second.

So last nights result was an anomaly - except we all know the Dutch hate penalty shootouts!

Mark Egan said...

David,

I think youre probably remembering the stat from Soccernomics saying that 60% of the time, the team going first in a penalty shootout wins. I dont have the book to hand but that figure is apparently from a sample of 129 shootouts, which seems small. This website looks at a much larger sample of 689 shootouts and find the team going first only has a 52% chance of winning: http://thepowerofgoals.blogspot.fr/2012/07/soccernomics-and-penalty-shootouts.html

To be fair that person applies the same weights for a shootout in a World Cup final or a Johnson Paint Trophy game, which don't seem equivalent in terms of the pressure on the penalty-takers.

Greg Joslyn said...

You're looking at the football/soccer phenom from the perspective of the shooter but perhaps the goalkeeper's outlook-- identical to that of the putter, no?--has a bigger impact.

Mark Egan said...

That's a good point Greg. I havent seen analysis that broke down missing penalties into "missed by player / saved by keeper", so there might be some insight to be mined there. I would still guess that any 'pressure' effect is greater on the person taking the shot rather than the keeper - noone really expects the latter to make a save. In contrast, Baggio said he felt haunted for years after missing the final penalty in the 1994 World Cup Final.

john cochrane said...

Does the perspective actually matter? When you substitute the goalkeeper for the shooter, the statistics reverse but so does the win/loss. The left column becomes "percentage of saves to avoid a loss" and the right column becomes "percentage of saves to secure a win", or "par" and "birdie" in the gold parlance.

Once again we see that the individual in the high pressure situation fairs poorly.

Michael Daly said...

Wonder are the figures right. Looking at the last penalty across the 26 shootouts in the World Cup 15 were won by penalties scored and 11 were won by a final missed penalty. This doesn't consider penalties that were missed to win or scored to avoid losing but the contrast doesn't seem as stark.

Mark Egan said...

Here's the data source for anyone interested in following up on it
http://en.wikipedia.org/wiki/List_of_FIFA_World_Cup_penalty_shoot-outs

Leigh Caldwell said...

A possible confound: teams that are shoot to win are by definition ahead of the other team, therefore (presumably) better at taking penalties. Thus one would expect them to do better. Teams that miss and lose are, equivalently, worse.

I imagine it would be possible to design the data analysis to control for his, but the implication of the simple stat is that this hasn't been done. Any ideas?