Over the past few days, lower scores have been appearing more frequently on the national scoreboard. Are officials heeding some sort of dictum issued by the secret society of coaches, led by Tom Izzo? We can get a better idea by taking a closer look at the data. We can’t know about the secret society until we discover John Adams working at an East Lansing Chevron in March. But we can find some useful information in comparing the early trends this season with those of recent seasons.
For those suspecting that officials are cowering in the face of (very limited) criticism, you might cite the decreasing foul rate over the first two weeks of the season. However, foul rate always drops early in the season. The graph below shows how this season’s decrease compares to the drop over the past five seasons, using the daily average of all D-I vs. D-I games played on a particular day. Based on the similar trends, you might chalk up any adjustments being made this season as similar to whatever adjustments have been made in the past and not something unique to the current rules interpretations.
The season-long plot on the bottom tells us that in the past, some sort of equilibrium was reached right about finals week, and free throw rate remains constant after that, with a slight rise as the pressure of championship week approaches. Who knows how it will play out this season, but it seems clear that in a macro sense we’ve seen the worst of the whistles this season.
Changes in more fundamental aspects of the game are also consistent with previous seasons. Average tempo is gradually decreasing. Tuesday’s 68 D-I vs. D-I games featured an average tempo of 66.8 possessions per 40 minutes, the slowest-paced day of the season so far, and reminiscent of a typical day last season. But based on past seasons, tempo decreases markedly early in the season, and once the day-to-day noise is filtered out, the trend we’ve seen so far this season is no different than that found in recent seasons. If the trend continues to mirror previous seasons, this decline in tempo will persist well into February.
So Izzo’s right when he claims that games will get slower as the season progresses. But they always do. This will hardly be proof that the new interpretations are a bad idea.
Opposing the decrease in pace is an increase in efficiency. While average efficiency is up over last season, the day-to-day trend is nearly identical to an average of the five previous seasons. In the past, efficiency continues to increase throughout the season although the rate of increase becomes flatter with time. On Monday, teams scored an average of 1.071 points per possession, the second-highest daily mark of the season. Those kinds of days may not become the norm, but they may happen more regularly going forward.
In most ways, trends are matching what has occurred in the past, but there’s at least one area where they’re not. Turnover rate started the season at stunningly low levels. There hasn’t been a single day so far where teams have collectively committed turnovers on at least 19 percent of possessions. There hasn’t been a season over the last decade where the average has been below 20, so clearly something is different in this area. The past five seasons have provided a consistent signal where turnover rate decreases over the course of the season. But this season, the opposite may be occurring. The normal mechanism for the increased in efficiency is a rise in shooting coupled with better ball security. With the latter potentially moving in the opposite direction, efficiency may not show its usual rise the rest of the season.
If the difference in the trend of turnover rate is real, it tells me that defenses are adjusting to the new rules interpretations, and not necessarily in the way that coaches like Izzo and Larry Eustachy fear. We may be on the path to a more free-flowing game, with more scoring and a less drastic drop in turnover rate than it looks based on the early data. Sure, there will be a few more fouls called, but we’ll see fewer players in foul trouble as the season continues, as was the case in previous seasons.
One other constant between this season and previous is that coaches, players, media, and fans will complain about the officiating. If the officials hadn’t changed their approach, we would have heard how college basketball is the roughest form of the sport played anywhere on the planet. So frankly, I’d prefer to evaluate this new era of hoops using data rather than comments from coaches, even those as respected as Tom Izzo.