Hot Hand red book cover and author Ben Cohen headshot

The Hot Hand is real (with the research to prove it)

People in a rhythm get better at whatever skill they’re using.

This intuitive idea was assumed enough that the catchy phrase “the hot hand” traveled from sports to countless other disciplines. Then research seemed to overturn its reality. Decades later, the research proved our instincts out.

That journey and research on streaks makes the bulk of the 2020 book The Hot Hand by sports journalist Ben Cohen. It may not have needed to be a full-length book, but I enjoyed it and appreciated the research he referenced, though much of it was familiar.

More broadly, the author argues our sense of randomness is all wrong. For example, if truly random, a playlist should alternate artists, a roulette wheel can’t have a streak and an immigration judge expects to have an even split of cases accepted and rejected. This confuses the law of small numbers and the law of big ones. It’s also why we are so prone to fall for the hot hand fallacy — and the related gamblers fallacy.

For future reference I share my notes from his book below.

My notes:

  • Mark Turmell and Sneakers: he went on to create the video game NBA Jam that defined “the hot hand” for a generation of kids turned adults
  • Sports and hot hand
  • Influential 1985 paper that said no such thing as a hot hand: 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: 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.
  • Stephen Curry’s legendary 2013 MSG game that brought him to stardom
  • But then NBA since 2013 has added cameras to get better data and did find slight correlation to hot hand
  • 2016 study showing immigration judges are less likely to give asylum if they’ve given 2-3 prior asylum grantees (though each case should be unrelated, they internalize the pattern)
  • 2015 coin flip paper showing probability is different
  • Dashun Wang: success comes in bunches (Einstein’s annual mirabils) 90% of financially successful artists, published scientists and directors with theatrical releases had a “hot hand,” of three or more works at a higher level than the rest. No prediction of when, so the only prediction of not getting there is to stop creating
  • Advice: Resources come to you when that hot hand comes so use it
  • Hic incipit pestis
  • James Shapiro tracked the chunking of Shakespeare’s work: His best work didn’t steadily come, but they chunked together
  • Romeo and Juliet has plague plot twist (quarantine is why Romeo doesn’t recieve the letter)
  • We don’t like true randomness! Fisher-Yates Shuffle powered the Spotify algorithm; Steve Jobs announced Smart Shuffle to control multiple artists in a row even though that isn’t random ; Lukas Polacek Mr Shuffle (we attribute patterns where there are none)
  • 1974 Tversjy and Kahneman classic paper in cognitive psychology: law of small numbers
  • Andreas Wilke: pattern seeking like hot hand has evolutionary benefits because nature is not evenly distributed
  • Ben Hayden monkey hot hand experiment shows monkeys have same hot hand pattern bias
  • Harvey Pollack 76ers data for Gilovich experiment
  • People expect numbers that are random in the longterm to be random in the short term too (but they aren’t)
  • Famous Fama paper “ the behavior of stock market prices” notes efficient market theory
  • Principles over patterns
  • Stock picking has no hot hand, like farming
  • (My note: The author’s farming chapter about Nick Hagan losing his sugar beet crop from a flood but doesn’t mention any crop insurance; just fulfilling the American self-made fable)
  • Sundali and Croson gamblers fallacy (no control) : three roulette wheel on black you bet on red (corollary to hot hand: make three shots we expect to make a fourth -have control );
  • In 1814 Pierre Simon Laplace said similar: “ the past ought to have no influence upon the future”
  • Philosophical essay on probabilities
  • 80% people left roulette table after a loss
  • Refugee Roulette paper: the judge was a greater predictor of asylum than any other quality or variability including status and country of origin; if a judge already approved he is less likely to approve the next (Moskowitz argues all cases should be heard twice and in different orders to remove bias)
  • Raoul Wallenberg
  • Moneyball changed everything in sports
  • Ezekowitz the young student who had the SportVU data to overturn the famous Tversky paper on hot hand; they could now control for how hot hand shooters take harder shots, layups vs three pointers (Simple Heat vs Complex Heat
  • Makinen and Kaplan data to asses Wallenberg in Soviet prison
  • Bill James godfather of sabermetrics: the Tversky hot hand paper only said they hadn’t found it (overstated by saying it didn’t exist); absence of evidence, not evidence of absence
  • Hot hand in basketball better defined: You are 1.2% likelier to make a shot if you made 1 in last 4 shots; 2.4% more likely If you made 2 of last 4
  • Miller and Sanjuro paper about coin flipping. Chance of getting a heads after another heads is less than 50% (watching Craig Hodges in 3pt contest)
  • “The proportion of hits after hits in a finite sequence is expected to be less than 50%” so if your shooting percentage remains the same you are not; their paper looked back at Tversky data to show players were actually 12% more likely to hit when hot (huge jump)

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