Before I start: I made a video explaining these charts and some of concepts behind the article. Feel free to take a look.
Comeback time! Okay, maybe not...
It’s been recently noted that the Spurs have not excelled at winning close games this season. A common statistic shared through the fanbase is that the Spurs are 2-37 in games when behind at the start of the fourth quarter. A 5% winning percentage is disheartening for those hoping for their favorite team to come back to win. But, despite the Spurs win percentage being notably awful, I would remiss if I didn’t note that 82% of teams behind in the score when entering the 4th quarter go on to lose the game. In fact, in the current season, only 1 in 6 have won the game. Regardless, San Antonio has been dreadful this year in tight games and for this Professor’s Corner we’re going to swallow that jagged pill and examine how the spurs rank in the league in the tight, high-impact possessions.
On Darryl Blackport’s site pbpstats.com he allows the user to view stats based upon the “leverage” of the possession in which the stat occurred. Leverage, as he defines it as, “how each much possession impacts win probability.” In Blackport’s model each possession is evaluated by the three qualities of score margin, time remaining, and the win probability based on the money line odds (pre-game). He then divides all possessions into how much each influences win probability and separates the into 4 levels.
1. Low. Primarily seen at the end of games in which the game outcome is rather set (comparable to “garbage time”) .
2. Medium. Most of the possessions in an NBA game.
3. High and Very High (these two levels merged). These are the possession seen in the last few minutes of tight games (I have combined these 2 levels will refer to the combined as high in this article)
One of the best ways to win basketball games is to score lots of points. This chart displays offensive efficiency (points per 100 possessions) across the league for low, medium, and high leverage possessions. The Spurs are among the rare few teams that have scored more efficiently in low leverage minutes in comparison to their overall average (give some credit to Jock Landale, Tre Jones, and Keita Bates-Diop for this). The bulk of the NBA game is spent in medium leverage minutes and in these the Spurs are slightly above league average with a rating of 113.2 (18th). Unfortunately, the Spurs offensive efficiency plummets to 26th in league in high leverage possessions.
Having one the worse offensive efficiencies in high leverage possessions likely agrees with the “eye test” of most diehard Spurs fans hoping for, but not getting, those 4th quarter comebacks. The largest predictor of offensive performance is shooting accuracy and the chart below shows a similar pattern to the previous. The Spurs are 22nd in the league in true shooting percentage (55.4%) in medium leverage possessions. Across the league, as teams encounter high-leverage possessions, most teams display a decline in true shooting percentage with league average reduction of -2.4%. But the Spurs display the 4th most precipitous decline in the NBA of -7.6% (55.6% —> 48.7%).
Turnovers can also be complicit in the reduction of offensive efficiency. The Spurs have the 4th best turnover rate in the NBA in medium leverage possessions of 12.7 per 100 possessions (league average of 14.0). Unfortunately, in high leverage possessions, the Spurs drop to 24th in the league in turnover rate (14.1 vs league average of 12.4). Hey…if you read that closely you might have noticed something. The league average in turnover rate DECREASES in high leverage possessions. That’s correct. Teams with skilled, potent lead handlers like the Lakers (Lebron), Suns (CP3), Raptors (Freddy All-Star), Bulls (DeMar), and Max (Luka) show significant decreases in turnover rate when the games get tight.
The chart above displays turnover rate in medium and high level possession using two different plotting methods. Line charts (left) are excellent to show how data transitions from one experimental state to the next. For example, it becomes clear how drastically the Lakers decrease their turnover rate in high-impact possession. It’s also very apparent how Detroit, with its rookie point guard, heads in the opposite direction. The vertical scatter plots (right) are excellent for showing averages and variance without the clutter of lines. In this plot it’s clear to see that the Spurs are one of five teams that increase their turnover rate in tight possessions.
Assisted Baskets in Tight Games
The final factor I would like to address is the relationship between assists and leverage. The Spurs nearly lead the NBA in the percent of baskets that are assisted. Specifically, the spurs are 2nd in the percentage of 2-point shots that are assisted and 1st in the percent of 3-points shots. Almost more than any team the Spurs use each other’s passing to score. Unfortunately, in high leverage possession this becomes more difficult as the defenses tighten and less cuts result in open shots. The league average decreases from 63.3% of baskets are assisted in medium leverage possession to 56.2% in high leverage possession. But the Spurs are far more drastic by dropping from 67.9% to 55.0%.
The chart displays a statistically significant linear regression relationship between the change in percent of assisted baskets to the offensive rating in high leverage possessions. The teams that show the greatest drop in the percent of assisted points score the least efficiently. This can be attributed to several factors and a significant contributor is that tighter defenses disproportionately disrupt teams that reply upon passing and cuts to be open. Style of play is influenced by the talent available. Teams with less effective ball-dominant scorers are forced to use movement to create opportunities. But these opportunities are diminished as teams go small and switch more often on defense in the end of game possessions, faster defenders switch and cuts are less effective
I’m haven’t shown anything you already didn’t know. The Spurs don’t have THAT guy right now and it’s up for debate if “he” is currently on the roster. Furthermore, it’s been a while. San Antonio has the 5th worst offensive rating in high leverage possessions over the previous two seasons. In fact, you would need to go back to the 2016-17 season in which they were the 5th best in the league. Of course, in that season, Kawhi averaged 25.5 points per game, had a very high 37% usage level in high leverage possessions, and LaMarcus blasted as 64% true shooting percentage when the games got tight.
I’ll be the first to admit this hasn’t been easy. Before March 11th I could have said to myself prior to the start of 32 different 4 quarters, “Hey, maybe the Spurs will come back and win?!” And I would have been wrong EVERY time. Fortunately, development is the goal here. Dejounte has the 4th highest usage in high leverage possession in the league this year. Had the Spurs not traded both Derrick White and DeMar DeRozan the Spurs development staff would be without those vital possessions as teachable moments to address this off-season. Talent is plentiful in the NBA. But winning is a skill the talented must learn. For example, Lebron James didn’t reach the NBA finals until his 4th season and everybody reading this article knows EXACTLY how that went (wink). Furthermore, he didn’t win his first game in the NBA finals until 4 years later...8 years after being drafted into the league! Thus, this can take time. Stay tough Spurs fans. “For the losers now will be later to win...”