

Gambler's fallacy trips up goalies - nkurz
http://news.sciencemag.org/biology/2014/07/gamblers-fallacy-trips-goalies

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pessimizer
The gambler's fantasy is a fantasy when you're trying to use it to predict a
coin flip, not what another human will do. The penalty kicker has to make the
same decision after looking at all previous results, and also may be making
decisions about where to kick based on the direction of the previous kicks.

If the kickers attempt to second-guess the "this side is due for a kick"
behavior by goalies, the goalies can try to second guess the kickers by
knowing that they are intentionally trying to avoid even distributions over a
moving historical window. It's the classic endless paper-rock-scissors
strategy discussion.

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jameskilton
From the OP, 70% of goalies chose the opposite direction of the previous kick
after 3 kicks. That's the "gambler's fallacy".

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jdminhbg
It's not, because the direction the penalty taker chooses is not a random
event. It may not be the optimum strategy, but it's not the gambler's fallacy.

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im3w1l
In regards to the ending counterpoint that a goaler has no chance of saving a
ball to the top third of the goal anyway:

A high ball should have a higher risk of missing the goal entirely. So the
better you can predict the keeper, the lower and safer shots you should be
able to take.

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dmourati
This was the point I was going to make. Even in this most recent world cup, we
saw plenty of outright misses by shooters. Better to put it on frame and force
the keeper to a save then to risk missing outright.

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CaveTech
Why? In the end, its only goals that matter. Everything else might as well be
counted as a miss.

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drhouse_md
This comment left under the article, which is supposedly bullshit, says it
all:

"Justin • 16 hours ago I have played goalkeeper for almost 30 years, and this
article makes no sense. We are not randomly guessing which way the kicker is
going. For important matches, you're going to study the other team's kickers
penalty history. Most players have a direction they feel more confident
kicking to. You pick that direction if the info is available. If not, I always
found that even if a kicker was trying to convince me of one direction, his
eyes would always give away the true direction right before the kick. Most
kickers need to do a visual check of their intended direction right before
striking.

I'll tell you what never in 30 years influenced my decision: the direction of
the previous kicker."

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altcognito
Watch the second half of kicks in the most recent World Cup, you can see that
some kickers seem to wait for any indication of the direction of the goalie
taking a dive in a particular direction.

[https://www.youtube.com/watch?v=wLlBIJekQTc](https://www.youtube.com/watch?v=wLlBIJekQTc)

At the level these guys play, they kick so fast it is difficult for the goalie
to get to the far reaches of the net even when they guess correctly, so I can
see why they jump early. In this situation, the bigger goalies definitely have
an advantage. Changing the direction you jump randomly isn't going to help
much.

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tedsanders
One counterintuitive piece of game theory trivia is that, in equilibrium,
penalty kickers should kick to their weaker sides more often than their
stronger sides.

In equilibrium, you should be indifferent to the goalkeeper's strategy, and if
you're better at kicking to the left, that means you should kick to the right
_more_ , not _less_.

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mhb
Also, the goalkeeper may have a weaker side.

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UweSchmidt
If I were the shooter I'd visibly flip a coin before walking to the penalty
point. I'd try to equally scan both sides of the goal, and do a neutral run-up
that hopefully wouldn't give away which side I picked.

This would neutralize most mindgames, statistical analysis and self-doubts.

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dmourati
First you'd have to practice enough kicks to be equally good at each side.
Most shooters have a preferred side of the goal.

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TillE
Players have a stronger _foot_. But it's not particularly difficult to use
that foot to strike the ball to one side or the other. It's a different
technique, but it's one that every professional footballer has inevitably
mastered.

