Examining how pace affects the KU basketball team's defense
Ready to see something strange?
OK, we're going to have to get a little bit nerdy, but stick with me, because this is interesting stuff.
Here is a graph I charted that shows the relationship between the pace of the Kansas basketball team's games (number of possessions) and KU's defensive efficiency (number of points given up per possession).
Notice the downward trend? We'll get a little more into what this might mean later.
The confidence level of this data is 99 percent*, meaning there is only a one-percent chance that the trend of this graph is due to chance.
* — In many studies, a 95-percent confidence level is needed to prove the data is correlated.
What's interesting is that this kind of a correlation doesn't happen often. I checked out the Game Plan section for each Big 12 team on KenPom.com, and no other conference team had a correlation between pace and offensive or defensive efficiency with a confidence level of 95 percent or better.
Yet, KU's correlation between pace and defensive efficiency had a confidence level of 99 percent.
Just for good measure, I wanted to test to make sure our numbers were accurate.
Webprince from the KUsports.com message boards (You can read his KU basketball-based statistical analysis on his blog, Sports and Numbers) provided me with the adjusted defensive efficiency numbers from each game. This rewards KU for playing better defense against tougher offensive teams, and penalizes it for playing weaker defense against poor offensive teams. It also takes into account where a game is played (road, home, etc.).
The graph looks nearly the same.
The confidence level of this data is 98.4 percent. Again, we have a correlation.
OK, let's take a step back and examine what this means. It could be one of two things.
1. Slower tempo is causing KU's opponents to score more points per possession.
2. Correlation does not equal causation, meaning that something else is causing the better opponents' efficiency that happens to coincide with slower tempo.
But what could it be?
Here are two of my own guesses:
1. Though KU is a good defensive team, it does not force many turnovers. The statistics back this up, as KU's opponents turn it over on 20.7 percent of their possessions (173rd nationally).
Because of KU's inability to get those turnovers, teams that are patient don't have a great risk of turning it over, and therefore have a greater likelihood of getting a better shot.
Webprince provided me a statistic that might back this claim up.
Through running his numbers, he found that KU's pace and opponents' turnover percentage was positively correlated with a 95.9 percent significance.
In English? As the pace goes up, KU's opponents' turnover percentage goes up. But as the pace goes down, KU's opponents' turnover percentage goes down.
This would seem counter to what I would guess. You would think fewer possessions in a game would mean that the possessions would be longer. And the longer the possessions are, the more likely a team would be to turn it over against KU.
The numbers suggest the opposite. The fewer the possessions in a game, the less likely a team is to turn the ball over against KU.
Here's a second guess to explain our data above:
2. KU's players don't defend well on long defensive possessions. Hypothetically, this could be because of fatigue.
KU has a relatively short bench at this time (31.2 percent of its minutes come from the bench, which is 183rd nationally). So is it possible that KU's players could be tiring after having to defend for 25-35 seconds?*
* — I know a lot of folks weren't happy with Colorado coach Jeff Bzdelik's comments after last game when he said: "Well, Kansas doesn’t want to guard our stuff. They hate that. So, you can’t accommodate them by taking quick shots and letting them off the hook. You need to make them defend.”
He's looking smarter toward the end of this blog, isn't he?
It's interesting to think that KU might want to try to speed teams up not because it will play better offensively, but instead, because it will play better defensively.
Any other theories out there to explain the numbers above?