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How Will A 14-Second Shot Clock After Offensive Rebounds Impact The NBA?


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I am not a particularly talented basketball player. I’m not bad, necessarily, I just lack in talent and finesse and have to make up for it with effort and borderline illegal defense. I belong on the Maine Red Claws, in other words. At a recent 3-on-3 tournament I host every year, I learned that next summer I’ll need to demand cell phones be turned off — someone caught video of me coming down with an offensive rebound, pump-faking to no avail, and then just sort of freezing on the block. I had no shot, I had no passing option, and for whatever reason I completely forgot I was allowed to dribble. It all took about seven seconds and felt like 20.

In other words, I’m exactly the type of player the NBA is considering legislating out. Granted, they’ve long since created a barrier to 5’10 try-hards without much skill making the league. Now, it seems they’d like to cut down on the option for the play immediately following an offensive rebound to be dragged out.

According to multiple reports, the NBA’s Competition Committee has recommended that the shot clock only be reset to 14 seconds following an offensive rebound beginning this year, not the full 24 seconds to which we’re accustomed. Adrian Wojnarowski of ESPN has reported that the change, among others, is expected to pass when the league’s Board of Governors votes on the proposal at meetings taking place Thursday and Friday (a two-thirds majority is required to pass the change).

There are a number of ways to look at the change in the post-rebound shot clock, and the exact macro outcome won’t be clear for some time. The league’s thinking appears to be that a shorter clock after a rebound will induce more shot attempts and a more up-tempo pace of play on offense, particularly late in games when the team ahead won’t be able to use a rebound as a means of running out additional clock.

Counter-points exist, to where a new offensive rebounds equilibrium may take some time. Some factors to consider:

1. In theory, a shorter shot clock after an offensive rebound decreases the value of an offensive rebound. With NBA teams already devaluing the offensive rebound to prioritize transition defense, it’s possible that decreasing the value of an offensive rebound further dis-incentivizes teams to crash the glass.

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2. Some of that change in offensive rebounding philosophy has come due to the increased volume of three-point shooting. Yes, a higher-efficiency scoring environment puts extra value on each shooting possession, but the trajectory of rebounds on longer shots is more difficult to predict*, therefore making offensive rebounds more difficult to secure. This study, for example, looked at the additional rebounders required to secure offensive rebounds on longer shots. Transition scoring opportunities have also become more valuable with the rise in three-point volume and early-clock attempts.

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(* — The original Sloan paper this was referencing is no longer online; a good summary can be found here.)

3. It is possible a shorter clock provides an incentive for more immediate putback attempts at the expense of threes following offensive rebounds rather than changing the appetite for offensive rebounds in general. However, if teams have the perception that offensive rebounds are both more difficult and less valuable, the pace-of-play argument in favor of the rule change may be moot. If teams aren’t crashing the offensive glass, that means they’re getting back on defense in transition, and better transition defense would mean more possessions are forced into half-court scenarios, which are, obviously, played out at a slower tempo than the transition game.

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As an aside, the league as a whole used 14.7 seconds per possession last year, but that number was 9.3 seconds after a turnover, 11.4 seconds after a live defensive rebound, and 17.5 seconds after a make or dead ball, per Inpredictable.

4. This may be mitigated some by the fact that teams are most efficient offensively early in the shot clock, anyway. That is, the value of a possession dwindles some as the shot clock runs out, and so an offensive rebound — which provides better court position against a scrambled defense than a regular possession — with 14 seconds is still quite valuable.

Blake Murphy

Further, the league scored 1.11 points per-possession on putback opportunities, per data from NBA.com.

5. There’s also a scenario in which, if defensive teams respond to decreased offensive rebounding effort by cheating more to get out in transition, offensive rebounds become “easier” for elite offensive rebounders. Players like Andre Drummond, Jonas Valanciunas, or Clint Capela — who rank among the league’s best on the offensive glass — have some skill to score quickly on putbacks, and are often their team’s only crasher. In this scenario, they could play similar roles and have even better output. Teams like Oklahoma City probably just value the extra possession enough to not fundamentally change their approach, too.

League-wide, 58.3 percent of offensive rebounds were contested last year, while only 33.5 percent of offensive rebounding chances resulted in an offensive rebound, per data from NBA.com. Drummond, as an example of what an elite rebounder can do, had 68.7 percent of his offensive rebounds come while contested and pulled in nearly half of the offensive rebounds he contested for. Valanciunas, meanwhile, scored 1.18 points per-putback despite 73.2 percent of his offensive rebounds being contested. A handful of other centers grade well, including Steven Adams, Nikola Jokic, and Enes Kanter. The response to the rule change could be quite personnel-driven.

6. There is some precedent the NBA can look to in order to determine how this change might impact their games. That’s a large part of what the G League is for, and the G League has been operating with a 14-second post-rebound shot clock for the past two seasons as a test run for the idea. (It has also been trialed at Summer League, while FIBA has operated under this rule since 2014.)

The G League had a higher offensive rebounding rate than the NBA the last two seasons, but that’s to be expected, because it always has. Not only is rebounding the most abundant skill on the G League market at a given time, that league’s general pace of play and slightly greater focus on the offensive end tilt the accounting. What’s perhaps most interesting is that the G League’s offensive rebound rate was declining along with the NBA’s for the last decade until there was a brief post-rule change spike, then a continuation of the trend.

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The change in the G League didn’t make a material change in the league’s offensive rebounding environment that wouldn’t have happened otherwise, it seems. We can dig one step further and see what it might look like, and as it turns out, most NBA offensive rebounds result in quick possessions, as you’d expect. Based on 2017-18 play-by-play data provided by PBPStats.com, those late-clock possessions are also fairly low yield; usually, you’re better off getting that shot up quickly, anyway.

Blake Murphy

7. It’s also possible the league is not particularly concerned about the impact of this rule over the first 46 minutes or so of a game, where whatever equilibrium the league finds won’t be a huge change or that big a deal. If the focus is almost entirely at end-of-game scenarios, then the benefits of the change are more pronounced – teams can’t chew up that extra bit of clock, there are more possessions and therefore more opportunity for comebacks.

Last year, the league offensive rebounding rate in situations defined by NBA.com as “clutch” grew to 25, up from 22.3 percent overall. Interestingly, though, the offensive rebound rate was just 22.1 percent for teams ahead by five points or fewer in the last five minutes of the game; most of the spike in late offensive rebounds came from the teams that were trailing (27.8 percent), apparently more willing to sacrifice transition defense to extend a possession.

Even in the final minute of a game within five points, the team ahead didn’t haul in clock-killing offensive rebounds much (21.6 percent). It’s still worth noting that those late-and-clutch offensive rebounds while ahead are valuable, and my own pass-through of the data shows that teams up by five or fewer in the fourth quarter held an offensive rebound longer on average (5.47 seconds versus 4.53 seconds for all offensive rebounds).

It sounds likely that the NBA will pass the rule change for this coming season and that the league will now play with a 14-second shot clock following offensive rebounds. The overall impact will be fairly subtle, both in terms of board-crashing incentives, speed of play, and what happens once a team comes up with an offensive rebound. More notably, I’m in a lot of trouble if 3-on-3 tournaments start adopting it.

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