GoAUpher: Bumping for the wonderful use of advanced stats. Mmmmmmmm, advanced stats....
While the focus of the media and this blog remains rightly centered on Minnesota football, it's also basketball season. The Gophers defeated Lehigh 81-62 in a contest that was never in doubt. Here's a basic statistical breakdown of the Gophers' offense.
A Reasonably brief review of Tempo-Free statistics
If you already know about tempo-free statistics, the following can be skipped.
Like baseball, basketball statistics have advanced considerably over the last decade. The biggest change in thinking about a basketball game is to consider the game as a series of possessions, and evaluate teams based on their success in scoring per possession, also known as their efficiency. This idea isn't novel. Dean Smith evaluated his teams this way his entire career, and many coaches have implicitly or explicitly acknowledged the benefits of thinking about the game as a series of possessions. Based on interviews Coach Pitino is one of them.
A possession is defined as the period of time between the offense having the ball until the other team gains control back. One consequence of this definition is that both teams have (almost always) the same number of possessions in a game. A possession can end in one of three ways: a made shot (including free throws), a missed shot that is rebounded by the defense, and a turnover by the offense. Offensive rebounds do not start a new possession because the offensive team has never relinquished control of the ball. Normalizing by possession allows us to compare teams that play at different tempos, hence tempo-free statistics.
As John Madden would remind us the winning team is the one that scores more points. Therefore, the first evaluation of an offense is how efficient it is at putting points on the board. Formally, a team's offensive efficiency is the number of points scored per possession. This number is frequently multiplied by 100 to yield efficiency per 100 possessions. By using points per possession instead of points per game, we avoid the problem of comparing different qualities. A game against Indiana will generate more possessions than a game against Wisconsin. It doesn't make sense to say that since a team scored more points against Indiana than they did against Wisconsin the offense has problems.
The next four statistics, usually known as the the Four Factors measure specific elements of basketball that help define offensive efficiency. They are Effective Field Goal Percentage (eFG%), Turnover Rate (TO%), Offensive Rebounding Rate (OR%), and Free Throw Rate (FTR).
Obviously a three-point shot is more valuable than a two-point shot (by one point). Strangely, the basic box score doesn't make a distinction when calculating Field Goal Percentage (FG%), which is just the number of makes divided by the number of misses. This means that a team that takes a lot of three-point shots is almost always going to have a lower FG% than a team that primarily takes 10 footers. However, taking a lot of three-point shots is a calculated risk. A shooter who makes 6-18 from behind the three-point line scores as many points as a shooter who makes 9-18 from inside.
Effective Field Goal Percentage takes this basic mathematical fact into account. The formula for calculating is
Normally, the formula is multiplied by 100 to remove the decimals. All else being equal, the team with the higher eFG% should win a basketball game. Pitino's offense relies on taking lots of three-point shots, so looking at eFG% will also make more sense when evaluating how well the team is shooting the ball.
Turnover Rate measures the fraction of possession in which an offense turns the ball over. This stat will be particularly important for Pitino's Gophers because they play substantially faster than under Coach Smith. The turnover rate is simply
Offensive Rebounding Rate calculates the fraction of missed shots rebounded by an offense. Offensive rebounding is probably overvalued, and studies that look at correlations between winning and different statistical categories consistently rank offensive rebounding low. Some coaches coach their teams to just get back on defense instead of going for offensive rebounds, Brad Stevens when he was at Butler comes to mind. Teams that turn the ball over frequently or who have high shooting percentages will generate fewer rebound opportunities because offensive rebounds require teams to a) shoot the ball and b) miss. Nonetheless, an offensive rebound continues a possession and thus increases the possibility of scoring point. It is measured as
As with the other statistics, this is usually multiplied by 100.
Finally Free Throw Rate measures the ratio of Free Throw Attempts to Field Goal Attempts. The logic behind this statistic is that teams that generate a lot of free throw attempts are putting themselves in a position to score consistently. This statistic is biased towards teams who are more drive oriented, but that's not necessarily a big deal. The Free Throw Rate of a team is
How did the Gophers do in their first game?
Pretty well. The Gophers had 67 possessions and scored 81 points for a total of 1.202 PPP or an efficiency of 120.2. Lehigh isn't a strong team, but the Gophers were scoring their points by taking good shots. For the four factors, the Gophers' line (eFG/TO/OR/FTA) was 53.4/17.8/36.4/35.6. The TO% masks to a degree the difference between two halves. The Gophers only had 3 turnovers in the first half, and some of the turnovers in the second half were the result of trying to make an aggressive play. While I'm sure Coach Pitino wants to cut down on sloppy turnovers, I can't imagine he'll be too worried about turnovers that are the result of pushing the pace.
That's all well and good, but do you have a pretty picture?
Kind of! Below is a shot chart (homemade so there's some margin for error) for the Gophers against Lehigh. A shot chart is descriptive, not prescriptive. That is, it shows the effect of what the Gophers were doing on offense, but doesn't speak to how they played.
The most positive takeaway from this chart is that the Gophers rarely shot the ball from the mid-range. Mid range jump shots are the worst shot in basketball. They are nearly as difficult to make as a three-point shot, but do not have the reward of an additional point. Of the mid range shots taken, most of them were prayers taken with little time remaining on the shot clock. Second, note the distribution of shots in the paint. The Gophers were playing an undersized team, and responded by attacking the basket. Elliott Eliason did work in the post, and #Hollinsanity took the option to drive to the basket when available.
As I mentioned here Pitino's offense is basically Florida's with some tweaks. He wants to start a lot of offense from the defense, either through the press or long outlet passes to players leaking out. The shot chart shows that the Gophers were successful in creating lots of three-point shots and layups, precisely Billy Donovan's formula for success.
One little thing to be aware of is that the shot chart implicitly shows that Malik Smith is a college version of Nick Young. I didn't verify it, but I think he had more shots than passes.
The Gophers shouldn't be seriously challenged for the majority of the non-conference, so expect Pitino to continue to tinker with lineup combinations. Mo Walker's suspension means that the next few games will feature lineups that probably will not be playing frequently in the BIG season.
The offense didn't show a lot of different sets. They utilized two basic motion screen concepts, a double baseline screen and a set where the guards screened for each other in the middle of the court to free up a shooter on the wing. Happily, the outcome of these sets was almost never a mid range jumper. If the Gophers never shoot a designed mid range jumper again I will be ecstatic. Looking ahead, it is worth wondering how much more offense is put in place heading into the Maui Invitational. Some of the extended offensive droughts may have been because of the lack of variety which allowed Lehigh to adjust.