Back in March, FiveThirtyEight’s Benjamin Morris wrote an interesting article about the value of the steal. In his estimation, based on regressing box score stats to match on/off court data, the steal is much more valuable than any other single stat. His analysis pegs a marginal steal’s value at 9.1 points.
On the face of it, this sounds nuts. A typical possession leads to about a point, which a steal prevents. A typical possession that results from a steal is a good bit more efficient than a normal possession. I have no idea how much more efficient, but we’re estimating here. I’ll be generous and call it 1.75 points per possession. That assumes a two-pointer on 7 of every 8 steals, which is an exaggeration for sure. Whatever the case, we’ll say it comes to 2.75 point swing per steal.
We’ve still got a ways to go to 9.1, and Morris offers a couple other factors. First, this is not the literal point value of a steal, but its weighting in predicting the on/off value of a player. So those nine points are at least partly a reflection of the fact that players who get more steals tend to be better in other ways defensively. Moreover, trying and whiffing on a steal can screw up a team’s defense, but it doesn’t kill the possession the way a missed shot does, so the opportunity cost is lower.
Third, steals are more, as Morris puts it, irreplaceable than other statistics. Taking a scorer off the floor will usually lead to the other players scoring more. That’s not the case with steals. Fourth, though Morris doesn’t mention it, steals have intangible effects: they cause the offense to press and hesitate and ultimately prevent precise execution. Having Ricky Rubio on the floor has an effect analogous to the effect of an elite rim protector.
This is all relevant because the Trail Blazers finished dead last in steals this season. In fact, they effectively tied the 07-08 Blazers for fewest steals per game in NBA history. They were also bad at defense. Those two facts are related; deciding which way the correlation runs is trickier, and also crucial to the Trail Blazers’ development.
First, it’s important to note that the Trail Blazers’ low steals rate is partly a choice. Back in February, Zach Lowe explained that the Trail Blazers are maybe “the most ‘conservative’ defensive team ever.” Not gambling for steals is a part of that. Wesley Matthews has averaged 1.3 and 1.5 steals per game the two seasons before this one. Splitting the difference and comparing it to this year’s figure of 0.9 per game suggests that Matthews alone lost 41 steals this year in service of careful defense.
This is simple, reductive math, and there are other factors at play, but we can assume some significant number of steals are conceded by choice. The question then becomes whether Terry Stotts ought to encourage more gambling by his perimeter defenders. I don’t think Stotts set out to be dead last in steals, but he’s probably okay with being near the bottom, and we can assume that there is a tradeoff– more steals would mean conceding more made shots, probably.
But I think there has to be a tipping point somewhere, and the Blazers straddle that line. An example: the Blazers never hedge on the pick and roll, which prevents the point guard from slipping into the middle and scoring at the rim. At some point, though, that effect is offset by the extra comfort the point guard has because he only has to navigate one guy in front of him. Another: you don’t want your center to chase blocks by sacrificing position, but at some point you’re losing out on the psychological edge you get from having a giant scary center swatting dudes’ shots.
In the same vein, the Trail Blazers don’t want their guards to get out of position gambling for steals. But it’s necessary to have that threat in the back of the ball-handler’s mind. There is no way of knowing whether the Trail Blazers are at that tipping point, but it’s likely; their steal-aversion is extreme enough that no one is scared of having his pocket picked or throwing an interception.
Of course, none of these decisions are made in a vacuum. The Trail Blazers have personnel problems that limit their ability to generate steals. Damian Lillard, the point guard and therefore the guy with the most opportunities to steal the ball, does not. And the Trail Blazers wouldn’t want him to– his defensive positioning is already bad enough without him throwing himself out of position trying for steals. Nicolas Batum and Matthews are fine as they go, but neither makes it the focus of his defensive efforts. I’ve always loved watching LaMarcus Aldridge’s quick hands, but there is only so much he can do as a power forward
It remains unclear what exactly constitutes those 9.1 points. Even if we assume something lower than that (9.1 is pretty outrageous, not that I have the statistical chops to say anything for certain), they’re clearly important. The Blazers ought to hope it’s more “good defenders get steals” than “steals make good defenders,” because I’m not sure they can reasonably generate more steals without compromising the scheme. Portland was 45 steals behind the 29th-ranked Bobcats this year. I don’t know if this is a symptom or a cause of the Blazers’ bad defense, but how the team addresses this need might make or break the team’s defense in the seasons to come.