What is... | October 23, 2018

What is the hot hand fallacy?

It can be easy to put your faith in a winning streak (until it stops). Jess Exton sums up the research.


Have you ever felt like you were on a winning streak? The so-called “hot hand” fallacy refers to a perception that once you’ve started to score, you’ll keep hitting those shots: winning big, over and over.

It’s known as a fallacy because research has suggested this feeling is an illusion. Yet some more recent studies have found the opposite - that perhaps the “hot hand” phenomenon does exist after all.

What are your chances?
Those who maintain “hot hand” is a fallacy typically refer to a 1985 study on the “hot hand” in NBA basketball, conducted by Thomas Gilovich, Robert Vallone and Amos Tversky. “Basketball players and fans alike tend to believe that a player's chance of hitting a shot are greater following a hit than following a miss on the previous shot,” they wrote.

In other words, experiencing a string of wins encourages players – and fans – to expect continued success. This makes the probability of that player scoring another goal seem greater than it actually is; they’re on a roll, they’re running “hot”. Other research seemed in line with these conclusions.

Perhaps unsurprisingly, basketball players who believed they’d experienced “hot hand” initially dismissed these results. But, as every psychologist knows, people just don’t like to be proven wrong – and their protests largely fell on deaf ears.

Feelings … and other factors
And then something else happened: a new study in 2014 completed some more thorough analysis. This new study also took into account how basketball players actually react to their own perceived “hotness” and how other players react as well.

Andrew Bocskocsky, John Ezekowitz, and Carolyn Stein performed the new research using a dataset of more than 83,000 shots from the 2012-2013 NBA season, tracking both the players and the ball.

“We show that players who have outperformed over recent shots shoot from significantly further away, face tighter defence, and are more likely to take their team’s next shot,” they explain in this write-up. “We challenge the belief that ‘hot hand’ is a fallacy.”

They showed that players who were “outperforming” continued to do so by a small but significant amount, taking into account the difficulty of the present shot.

More recent studies have found the opposite - that perhaps the "hot hand" does exist after all.

More than an illusion
It was shown that a player who hits four shots in a row is about two percent more likely to hit the next one than one who has hit just two of the last four shots. This means there is in fact a small but real improvement in the player’s chances of making the next hoop.

In 2015, another study took a detailed look at the probability of consecutive performances within the context of multiple coin tosses. This was another way to test the existence of a “hot hand” effect.

If a person tossed a coin three times and got heads each time, what is the probability of flipping a fourth head? Researchers Joshua Miller and Adam Sanjurgo showed that the chance of continued performance like this is smaller than 50%. It was suggested that some type of “cold hand” could be at play.

Let’s try that one again
Importantly, they were not just looking at the chance of flipping a single coin and getting heads once but of coming up heads repeatedly and continuously in a limited number of tosses. This suggests the effect may be more than random.

You can read more about this study here. Miller and Sanjurgo applied their probability analysis to a range of data, including that which was used to initially suggest the hot hand was an illusion.

They proved the "hot hand" exists. The effect varies and will be determined by a range of variables, including skill levels, if applied to a game such as basketball. Nevertheless, consecutively making a shot multiple times does indeed affect the chance of scoring on the next go.

And there’s more
And when we think we are on a winning streak this feeling can mean we act differently - expecting to make it big. We may have feelings of overconfidence, even in games of pure chance.

Confirmation bias sees us only looking for information or events that will support our current views (rather than challenging them). And when we are continually performing we can also start to feel like we are in control, even if this is purely an illusion.  

We can also tend to underestimate how “clumpy” patterns can be. It’s natural to think you’ve struck some kind of pattern, when heads appear four times in a row or you win yet another raffle.

So even though the odds of consecutive wins may have an effect, it might still be just chance. While research continues, it might be better not to push your luck too far, let alone your finances.

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Jessica Exton
Jessica Exton

Behavioural scientist at ING
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