Do hot streaks exist?

The enlightened conventional wisdom is that hot streaks in sports don't exist. But, as I pointed out in February, that is probably simplistic. 

Are ‘Hot Hands’ in Sports a Real Thing? 

By GRETCHEN REYNOLDS 

Winning streaks in sports may be more than just magical thinking, several new studies suggest. 

Whether you call them winning streaks, “hot hands” or being “in the zone,” most sports fans believe that players, and teams, tend to go on tears. ... 

But our faith in hot hands is challenged by a rich and well-regarded body of science over the past 30 years, much of it focused on basketball, that tells us our belief is mostly fallacious. ... 

Now, however, some new studies that use huge, previously unavailable data sets are suggesting that, in some instances, hands can ignite, and the success of one play can indeed affect the outcome of the next. 

In the most wide-ranging of the new studies, Gur Yaari, a computational biologist at Yale, and his colleagues gathered enormous amounts of data about an entire season’s worth of free throw shooting in the N.B.A. and 50,000 games bowled in the Professional Bowlers Association. Subjecting these numbers to extensive (and, to the layperson, inscrutable) statistical analysis, they tried to determine whether the success or failure of a free throw or a bowling frame depended on what had just happened in the competitor’s last attempt. ...

In these big sets of data, which were far larger than those used in, for instance, the 1985 basketball study, success did slightly increase the chances of subsequent success — though generally over a longer time frame than the next shot. Basketball players experienced statistically significant and recognizable hot periods over an entire game or two, during which they would hit more free throws than random chance would suggest. But they would not necessarily hit one free throw immediately after the last. ...

But if winning streaks have some rational basis, then by inference so would losing streaks, which makes the latest of the new studies, of basketball game play, particularly noteworthy. In that analysis, published last month in the journal Psychological Science, Yigal Attali, who holds a doctorate in cognitive psychology, scrutinized all available shooting statistics from the 2010-11 N.B.A. season. 

He found that a player who drained one shot was more likely than chance would suggest to take the team’s next shot — and also more likely than chance would suggest to miss it. ... 

The reason for this phenomenon might be both psychological and practical, Dr. Attali wrote; players seemed to take their second shots from farther out than their first ones, perhaps because they felt buoyed by that last success. They also were likely to be defended more vigorously after a successful shot, since defenders are as influenced by a belief in hot hands as anyone else. 

But what the findings underscore, more subtly, is that patterns do exist within the results. The players were more likely to miss after a successful shot. And this anti-hot hand phenomenon, said Dr. Yaari, who is familiar with the study, was itself a pattern. “It is not completely random and independent” of past results, he said. 

These new studies do not undermine the validity of the magisterial past research on hot hands, but expand and augment it, Dr. Yaari and the other authors say, adding even more human complexity. Yes, we probably imagine and desire patterns where they do not exist. But it may be that we also are capable of sensing and responding to some cues within games and activities that are almost too subtle for most collections of numbers to capture. 

“I think that our minds evolved to be sensitive to these kinds of patterns,” Dr. Yaari said, “since they occur frequently in nature.”

Cold streaks certainly exist, so maybe hot streaks are just the absence of cold streaks. 

Consider Pedro Martinez at the zenith of his pitching career, in the hitters park of Fenway during the steroid era of 1999-2003. Over those five years, he went 82-21 with a 2.10 ERA, 2.28 times better than the average pitcher in the league, which is astounding. In some ways, that's about as good as any pitcher has ever been. 

Yet, Martinez had numerous cold streaks during those five years where he didn't have even a chance of winning: during those five years, he missed about 40 starts, over 20% of his opportunities. 

Martinez is not very big for a pitcher (5'-11" and 170 pounds) and baseball teams have gotten more enlightened about not overstressing their aces. When Martinez would get slightly injured, the team would sit him down, maybe put him on the disabled list. In the past, the manager probably would have told him to man up and pitch through the pain. So, the more modern pattern is to have a Martinez pitch only when he was hot, and to yank him for a reliever or a substitute starter as soon as something goes off-kilter. 

In the past, Martinez would have had more cold streaks and hot streaks while he struggled through his troubles. Modern managing does a better job of getting pitchers out of the game entirely, so their cold streaks can only be inferred from starts missed. Now, it looks like Martinez was hot all the time for five straight years, but in reality he missed the equivalent of a full season over that half decade.