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The science behind streaks on and off the basketball court

In the seminal arcade video game, NBA Jam, a player making two shots in a row would begin "heating up," and after three shots they would go on an unstoppable shooting streak. But do these kinds of streaks exist in real life? Hari Sreenivasan spoke with Wall Street Journal reporter Ben Cohen about his new book, "The Hot Hand," and the implications of streaks both on and off the basketball court.

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  • Hari Sreenvivasan:

    Sports in the united states are finally back. Sort of.

    Baseball kicked off an abbreviated 60 game season this week, and basketball starts today with the WNBA, followed by the NBA later this week.

    Players, staff, and media are quarantined, everyone is tested for COVID-19 regularly, and the games are being played with no fans in attendance.

    But the extraordinary circumstances of this season won't change a familiar phenomenon: players will go on streaks where they just can't seem to miss.

    Athletes will tell you the so-called "hot hand" is undeniable, but how do you know when you have it? And, crucially, does it even exist?

    In a new book, Wall Street Journal reporter Ben Cohen chronicles the research behind these streaks. And in this interview taped right before the NBA season shut down in March, we started by talking about a virtual court.

  • Game sound:

    Stolen… he's heating up!

  • Hari Sreenvivasan:

    In the 1993 video game NBA Jam, teams of two play a souped-up, exaggerated version of basketball. But there was one feature of the game that basketball fans everywhere recognized: after a player made three shots in a row, he could not miss.

  • Game sound:

    "He's on fire!"

  • Ben Cohen:

    We wanted to get to that point where we heard those three magical words. This game was seductive to kids of a certain generation. And part of it was because of the hot hand.

  • Hari Sreenvivasan:

    That's the name of Ben Cohen's new book, which delves into a question that has vexed economists and psychologists for decades: whether "the hot hand" exists.

    While Cohen says that NBA Jam codified the hot hand for a generation of video game players, for many sports fans its existence is as simple as watching the Golden State Warriors' Stephen Curry.

    Cohen covers the NBA for the Wall Street Journal and he writes about a night in February of 2013 where Curry seemingly could not miss.

  • Doris Burke:

    That guy is hot!

  • Mark Jones:

    Curry for three, whoa!

  •  Hari Sreenvivasan:

    Curry made 11 of his 13 three pointers, finishing the night with 54 points, the most he has ever scored in one game. Curry's legendary hot hand that night helped propel him to superstardom.

  • Ben Cohen:

    In many ways, that game was an inflection point in his career. What he likes to say is that he doesn't know when he's going to be hot. He doesn't know where he's going to be hot. He doesn't know why he might be hot. But once he does get hot, he has to embrace it. And that's what he did that night against the Knicks.

  • Hari Sreenvivasan:

    But was Curry's performance the result of a hot hand, where making one basket made hitting the next one more likely? Or are we seeing patterns where there might just be a statistical anomaly?

  • Ben Cohen:

    There is a real generational debate about whether there is such a thing as the hot hand. And all of that started with the publication of a paper in 1985 with this counterintuitive conclusion, which is that there is no such thing as a hot hand. It's simply a misreading of randomness.

  • Hari Sreenvivasan:

    Psychologists Thomas Gilovich, Robert Vallone, and Amos Tversky had Cornell University undergraduates shoot baskets from where they statistically made about half of their shots.

    They also used data collected by the Philadelphia 76ers during the 1980-81 season. It was the only team in the NBA that kept track of consecutive shots during games.

  • Ben Cohen:

    Not too long ago, even just the basic chronology of basketball shots was this mother lode of data. And what happened once they analyzed that data was that they showed that you were actually no more likely to make your next shot after making two or three shots in a row.

  • Hari Sreenvivasan:

    Cohen says the finding of three academics did not necessarily change the minds of the basketball world.

  • Ben Cohen:

    One lucky reporter actually got to tell the great Boston Celtics coach, Red Auerbach about this paper. And Red Auerbach sort of sneered and says, like, 'what is this? I don't care about these professors. Like, they make a study. I couldn't care less.' And that was generally the view among basketball players because we'd all felt the hot hand, right? We'd seen the hot hand. And here were these professors coming along and telling us there was no such thing.

  • Hari Sreenvivasan:

    Cohen details how this is not just a phenomenon among athletes. From investors to gamblers to even artists, success often appears to come in bunches. But thinking you see a streak when you might just be seeing a pattern in randomness can also have negative consequences.

  • Ben Cohen:

    that is one of the central points of the original paper: not only is there no such thing as the hot hand, but believing in the hot hand is a costly illusion. Right?

  • Hari Sreenvivasan:

    Cohen writes about a 2016 study that looked at hundreds of thousands of asylum decisions by immigration judges

  • Ben Cohen:

    What they found is that when asylum judges grant asylum to two or three refuges in a row, they're much less likely to grant asylum to a fourth applicant.

  •  Hari Sreenivasan:

    Regardless of what the case is?

  •   Ben Cohen:

    Regardless of the merits of the case, the 'where' and the 'what' and the 'why' was actually less important than the 'when' in this case. Now that's crushing it. It's not Steph Curry missing a shot. It's maybe having to go back to their home country where they fear persecution. And the reason this happens is because these judges are trying to even out the probabilities in their own minds. Right. They feel like, 'I have given asylum three times in a row. I shouldn't give to a fourth. I should try to regress to the mean.'

  • Hari Sreenvivasan:

    In other words, judges don't want to look like they are on a streak. It's a similar perception to the one that makes us believe that a player who has made several shots in a row will make the next.

    But an NBA player shooting a basketball is not the same thing deciding an immigration case. And an advanced stat revolution in the NBA has upended research on the existence of the "hot hand."

  • Ben Cohen:

    What we have now is data that wasn't available to those researchers in their nerdiest wonkiest dreams like the world has changed. And sometimes when the world changes, you have to question long-held assumptions.

  • Hari Sreenvivasan:

    Since 2013, every arena in the NBA has had cameras that track all of the action on the court. The data allows for the quantification of exactly how hard each shot is; tracking precisely where a player is, and whether someone is trying to stop him.

  • Ben Cohen:

    These researchers found that you were actually slightly likely to make your next shot. The ball is not turning into a fireball, but this was some of the first evidence to come along to suggest that maybe our intuition was right all along. And in certain circumstances, there is such a thing as the hot hand.

  • Hari Sreenvivasan:

    This tracking data is not the only update to research on the hot hand. More recent evidence of its existence has come from a counter-intuitive finding by two economists using coin flips.

  • Ben Cohen:

    What they found was that if you flip coins in a sequence and you take the probability of getting a heads or tails after another heads or tails, it's actually not 50 percent, as we have been conditioned to believe forever. It's actually closer to 42 or 43 percent. It's mind boggling. It's kind of trippy math.

    Even people who have looked at this paper and studied it and peer reviewed it and published it have trouble wrapping their minds around it, but if you think about that in terms of the hot hand, it means that when you're shooting 50 percent, you're actually exceeding probability. Right? You are, as they might say, on fire. And everybody had missed this for 35 years because it's very counterintuitive, mathematically.

  • Hari Sreenivasan:

    It's a finding that made national news when it was published as a working paper in 2015, and it has caused the authors of the 1985 paper — which said there was no such thing as a hot hand — to reexamine their original findings.

  • Ben Cohen:

    They're still experimenting with the hot hand. I was up at Cornell to see a shooting experiment in a basketball gym, not unlike the one that happened 35 years ago. So where this data leads us, I don't think any of us quite know yet. But they are some of the people who are most anxious to find out.

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