Thursday, June 25, 2015

76er Statistician Harvey Pollack, Who Had a Hand in Hot-Hand Research, Dies at 93

As reported in newspapers yesterday, Philadelphia 76er statistician extraordinaire Harvey Pollack has died at age 93. In fact, it was Pollack's knack for quirky and exotic basketball statistics that greatly aided the first scholarly publication on hot-hand research.

The publication I'm referring to, of course, is Tom Gilovich, Robert Vallone, and Amos Tversky's 1985 article "The Hot Hand in Basketball: On the Misperception of Random Sequences," which was published in Cognitive Psychology (sometimes referred to as "GVT" in reference to the authors' last initials). Pollack is thanked in GVT's author notes, and here's why.

The GVT article included statistical analysis of three basketball-shooting compilations: field-goal shooting in 1980-81 Philadelphia 76er home games; free-throw shooting by the Boston Celtics in 1980-81 and 1981-82; and controlled shooting sessions with Cornell University men's and women's players.

Of crucial importance is that, except for Pollack and the 76ers, no NBA team kept sequential shooting data on field-goal attempts. Box scores tell us each player's number of total field-goal attempts and made attempts, but not the player's sequence (e.g., hit-miss-miss-hit-hit...). Only because Pollack kept sequential field-goal data for players was this aspect able to be feasibly incorporated into the GVT article.

Nowadays, play-by-play sheets are readily available on the Internet, which would make collecting player sequences reasonably doable. In the early 1980s, however, GVT's only alternative to Pollack's numbers would have been to watch large numbers of NBA games (not that they necessarily would have minded) and record sequential data on their own. As Gilovich confirmed for me yesterday, "Harvey was the guy without whom we could not have done our research. [I] owe him a lot!"

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