Before we start: I made a video explaining these graphs and some concepts behind the article. Don’t hesitate to take a look.
Back-to-school time! Well, maybe not…
It was recently noted that Spurs haven’t excelled at winning close games this season. A common stat shared by the fanbase is that Spurs are 2-37 in games when they are down at the start of the fourth quarter. A 5% winning percentage is disheartening to those hoping their favorite team will come back to win. But, while Spurs’ winning percentage is particularly awful, I would be remiss if I did not note that 82% of teams are behind in scoring when entering the 4and quarterback continue to lose the game. In fact, in the current season, only 1 in 6 have won the game. Either way, San Antonio has been abysmal this year in close games and for this teacher’s corner, we’re going to swallow that jagged pill and take a look at how the Spurs rank in the league in tight, high-impact possessions.
On Darryl Blackport’s pbpstats.com site, it allows the user to view statistics based on the “leverage” of the possession in which the statistic occurred. Leverage, as he defines it as “how each possession impacts the probability of winning. In the Blackport model, each possession is evaluated by the three qualities of scoring margin, time remaining and probability of winning based on money line odds (pre-game). It then divides all the possessions into how much each influences the probability of winning and separates them into 4 levels.
1. Low. Mostly seen at the end of games in which the outcome of the game is rather set (comparable to “trash time”).
2. Medium. Most possessions in an NBA game.
3. High and Very High (these two levels merge). These are the possessions seen in the last minutes of close games (I combined these 2 levels and I will talk about combined as high in this article)
One of the best ways to win basketball games is to score a lot of points. This graph displays offensive efficiency (points per 100 possessions) across the league for low, medium, and high leverage possessions. Spurs are among the few teams that have scored more effectively in minutes at low leverage compared to their overall average (give some credit to Jock Landale, Tre Jones and Keita Bates-Diop for that). Most of the NBA game is played in minutes at medium leverage and in those Spurs are slightly above the league average with a 113.2 rating (18and). Unfortunately, Spurs’ attacking efficiency drops to 26and in league in high leverage possessions.
Having one of the worst offensive efficiencies in high-leverage possessions probably agrees with the “eye test” of most diehard Spurs fans who hope for, but don’t get, these 4and quarter returns. The biggest predictor of offensive performance is shooting accuracy and the graph below shows a similar pattern to the previous one. Spurs turn 22n/a in the league in true shooting percentage (55.4%) in medium leverage possessions. Across the league, as teams encounter high leverage possessions, most teams are showing a decline in true shooting percentage with a league average reduction of -2.4%. But Spurs display the 4and steepest drop in the NBA of -7.6% (55.6% —> 48.7%).
Turnovers can also be complicit in reducing offensive effectiveness. The Spurs have the 4th best turnover rate in the NBA in average leveraged possessions of 12.7 per 100 possessions (league average of 14.0). Unfortunately, in high leverage possessions, Spurs drop to 24and in the league in turnover rate (14.1 against a league average of 12.4). Hey… if you read carefully, you might have noticed something. The league average turnover rate DECREASES in high leverage possessions. It’s correct. Teams with skilled and powerful point guards like the Lakers (Lebron), Suns (CP3), Raptors (Freddy All-Star), Bulls (DeMar) and Max (Luka) show a significant decrease in turnover rate when the matches get tight.
The graph above displays the turnover rate of mid and high tier possessions using two different plotting methods. Line graphs (left) are excellent for showing how data transitions from one experimental state to another. For example, it becomes clear how much the Lakers are reducing their turnover rate in high-impact possession. It’s also very obvious that Detroit, with its rookie point guard, is heading in the opposite direction. Vertical scatterplots (right) are great for showing means and variance without the clutter of lines. In this plot, it’s clear to see that Spurs are one of five teams increasing their turnover rate in tight possessions.
Baskets assisted in close games
The last factor I would like to discuss is the relationship between assists and leverage. The Spurs nearly lead the NBA in field goal assist percentage. Specifically, Spurs are 2nd in 2-point shot percentage assisted and 1st in 3-point shooting percentage. Almost more than any team, Spurs use each other’s passes to score. Unfortunately, in possession of high leverage, this becomes more difficult as defenses tighten and fewer cuts lead to open shots. The league average goes from 63.3% of field goals assisted in mid-leveraged possession to 56.2% in high-leveraged possession. But the Spurs are much more drastic, going from 67.9% to 55.0%.
The graph displays a statistically significant linear regression relationship between the percentage change in field goal assists and offensive rating in high leverage possessions. Teams with the biggest drop in assisted points percentage score the least effectively. This can be attributed to several factors and a significant contributor is that tighter defenses disproportionately disrupt responding teams when passing and cutting to be open. The style of play is influenced by the talent available. Teams with less effective scorers dominating the ball are forced to use movement to create chances. But those opportunities are reduced as teams get smaller and switch to defense more often late in the game, defenders change more quickly and cuts are less effective.
I haven’t shown anything that you don’t already know. Spurs don’t have THIS guy right now and it’s up for debate if “he” is currently on the roster. Besides, it’s been a while. San Antonio has the 5th-worst offensive rating in high-leverage possessions in the previous two seasons. In fact, one would have to go back to the 2016-17 season in which they were 5th best in the league. Of course, during this season, Kawhi averaged 25.5 points per game, had a very high usage level of 37% in high leverage possessions, and LaMarcus hit shooting percentage. 64% real when the games got tight.
I will be the first to admit that it has not been easy. Before March 11, I could have said to myself before the start of 32 4 different quarters: “Hey, maybe 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 use of high leverage possession in the league this year. If Spurs hadn’t traded both Derrick White and DeMar DeRozan, the Spurs development staff would be without those vital possessions as teachable moments to approach this offseason. Talent is abundant in the NBA. But winning is a skill the talented must learn. For example, Lebron James only reached the NBA Finals in his 4th season and anyone reading this article knows EXACTLY how it happened (wink). Plus, he didn’t win his first game in the NBA Finals until 4 years later… 8 years after being drafted into the league! So, it may take some time. Stay tough Spurs fans. “Because the losers now will be later to win…”