The hot (invisible?) hand: Can time sequence patterns of success/failure in sports be modeled as repeated random independent trials?

Abstract

The long lasting debate initiated by Gilovich, Vallone and Tversky in 1985 is revisited: does a "hot hand" phenomenon exist in sports? Hereby we come back to one of the cases analyzed by the original study, but with a much larger data set: all free throws taken during five regular seasons (2005/6-2009/10) of the National Basketball Association (NBA). Evidence supporting the existence of the "hot hand" phenomenon is provided. However, while statistical traces of this phenomenon are observed in the data, an open question still remains: are these non random patterns a result of "success breeds success" and "failure breeds failure" mechanisms or simply "better" and "worse" periods? Although free throws data is not adequate to answer this question in a definite way, we speculate based on it, that the latter is the dominant cause behind the appearance of the "hot hand" phenomenon in the data. © 2011 Yaari, Eisenmann.