NCAA Basketball: Was moving back 3-point line the right decision?

NCAA Basketball is moving back the 3-point line. What are the goals of this change and will it be successful?

This week, the NCAA Rules Oversight Panel agreed to move the NCAA Basketball men’s 3-point line back from 20 feet 9 inches to the international distance (22 feet 1 ¾ inches). This is the first change to the college line since it was moved back a foot prior to the 2008-09 season.

(Credit to KenPom for all statistics)

The goals of the change are open up the lane/create more offensive spacing and slow down the increasing prevalence of the 3-pointer in the college game.

Will the change accomplish the NCAA’s goals? Moving back the line should reduce 3-point attempts slightly, especially in the first season when teams are still adjusting to the distance. When the line was moved back prior to the 2008-09 season, this contributed to a dip in 3-point attempt rate from 34.5% to 33.1%. The rate didn’t get back to at least 34.5% until the 2015-16 season.

Regarding whether the change would create more spacing, this seems likely. Although a simplistic example, imagine four capable shooters spread around the 3-point arc, with the ball handler at the top of the key. None of the defenders will want to stray too far away from their assignments due to their shooting abilities, which will result in a significant amount of space in the lane.

Now imagine the same scenario, but the 3-point line has been moved back. The shooters, scattered around the arc, will now be a bit farther from the basket, and their defenders will move with them. This will result in even more open space inside the arc for the offense to operate. This is one of the goals of the rule change.

The only way the change doesn’t result in more spacing is if the shooters are significantly less effective at the longer distance. If they become significantly worse as shooting threats, the defenders will be able to back off them a bit, creating less room inside the arc.

It won’t be surprising at all if players shoot a worse percentage next season from the longer distance, but will the drop off be enough to neutralize the spacing benefits? Following the 2008-09 change, 3-point percentage declined from 35.1% to 34.2%, with offensive efficiency declining slightly as well from 101.8 to 101.4 (points per 100 possessions).

Overall, moving back the line should accomplish the NCAA’s objectives. It should not only reduce threes, but create more space inside the arc.

But are these changes necessary? It’s hard to argue the three hasn’t become a huge part of the college game. I did a deep dive here on how it is college basketball, not the NBA, where the “3-point revolution” has really taken off. At the same time, it’s not clear that the prominence of the 3-point shot has been poor for the game in general and/or made watching games less appealing.

In general, I think increasing offensive efficiency is good for the sport, and it makes sense that increasing spacing would accomplish this. As was touched on in the above example, increased spacing gives offenses more room to operate. If shooters can eventually knock down 3’s at comparable rates despite the longer distance, this should lead to improved offensive efficiency across the sport.

If 3-point percentage takes a significant dip next season, then there might be a correlated decline in overall efficiency. In the long-run however, the percentage should recover as players adjust to the distance.

For reference, below is the overall offensive efficiency for every season going back to 1997-98 (per KenPom).

Efficiency has been on a steady upward trend, and the increase in 3-point shooting has surely been a significant reason why. It will be interesting to see where efficiency ends up next season. Will the longer 3-point shot hurt offensive efficiency, at least temporarily? Or will the increased spacing immediately make offenses more productive?