Most
halftime shows include comments from former players and coaches about how teams
must “pick up the intensity” or “step up” in the second half. In basketball
games, analysts talk about strategies like “getting the ball inside” or “taking
better care of the basketball.”
While
such input from former players and coaches is valuable, it is far from complete
analysis. You need to get into the numbers for that to happen. Sports analytics provides powerful insight and
doesn’t need to involve anything complex. The concept of regression to the mean
reveals far more about what to expect in the second half, and only requires
comparing a few key stats.
Let’s
say one team shoots 8-for-10 from three-point range to grab a 10-point lead while
the other clanks 1-for-9. If both teams entered the contest shooting 40 percent
on the season, it is almost certain that both teams regress to the mean – the 40
percent mark – in the second half. Defense impacts these stats, but randomness
(or luck) is a huge factor in small samples. As more shots get taken, teams
should move toward their season percentage and cause the score to tighten up.
Free
throw percentages are another great stat to examine at halftime. Unlike
three-pointers, they aren’t defended. So randomness plays an even
greater role.
I
believe broadcasts will soon have a statistical expert offering such insight –
alongside coaches and/or former players – on halftime shows. But until that
happens, we can all do it ourselves.