Stephen Gould, continued
In his later years he developed an explanation for the appearance of complex animals based on his interest in baseball. Gould was fascinated with the question of why there have been no 0.400 hitters since Boston Red Sox Ted Williams, who hit 0.406 in 1941. Going into the last day of the season, Ted had a 0.401 average and the manager wanted to bench him to preserve the record. Williams would not hear of it. He played in both ends of a double header that last day, hitting 6 for 8. The closest anybody has come to matching this feat was George Brett in 1980 (0.390), Rod Carew in 1977 (0.388) and Williams himself in 1957 (0.388).
Gould believes the reason that the explanation is that the general level of play has improved over the decades since William’s feat. But the average batting average has not improved over the decades. Consider the League averages in the graph below:
There is no indication that batting averages in either League have increased meaningfully since 1941. What has changed is the variation in batting averages. It is now much more homogenous, which means that there are fewer really poor hitters now.
So how does this answer the 0.400 hitter question? There is less spread around the typical annual average of 0.260. This means that the right-hand tail of the curve (toward 0.400 hitting) has shifted toward the average, toward the left. Among the whole population of all baseball players, there are fewer hitters now out there on the right-hand tail who have a remote chance of hitting 0.400. Why there is less variability now is open to interesting debate, involving such things as uniform training methods, night baseball, better pitching, relief pitchers, and so on. You can read the whole story in his last book, Full House.
Gould is not the only baseball nut among scientists. He and a Nobel Prize winning physicist, Ed Purcell, published a paper on batting streaks and slumps. All of the streaks and slumps they measured fell well within the range of chance – except one. Joe Dimaggio’s streak of hitting in 56 straight games should not have happened by chance.
Love, hate, joy, envy, and respect are some of the many opinions that scientists have held of Stephen J. Gould. Despite the quaint and arcane nature of his primary research interest, the evolution of land snails, Gould had many ideas that expanded far beyond snails. He was a bold and creative thinker and his ideas – still being debated today – demanded consideration.
Baseball helps to illustrate Gould’s point that humans tend to ignore variation and focus on single measures, such as averages. This affects the way we view many things, from the stock market to evolution. Think about the bell-shaped curve. Most people think about the peak of the curve, which is the average for the "population" of all hitters. But what about the tails of the curve? The tails of the curve show that some hitters are more likely to have a much higher average. The data are far away from the average, but they are nonetheless real – and in baseball as in evolution, can be very important.