If you follow men’s college basketball, you’ve surely heard by now that the NCAA is finally moving back the three-point line. That won’t take effect in D2 and D3 until 2020, but D1 will use the new line this season. The move is from 20’ 9” to 22’ 1 ¾” (or 6.75 meters–the distance for FIBA and other international competition).
There has been some debate and discussion as to whether this move will matter a whole lot. Since it’s summer, and college basketball news is slow, it seems like a good time to dig into the impact this might have on the game. The NCAA used the FIBA line for the last two NITs, so we have 62 games-worth of a sample to look at. I wouldn’t be surprised if the move creates a domino effect and we see lots of subtle changes–creating more spacing could open up the lanes for drives and give us a boost in two-point percentage, for example–but if I looked at all of them we’d be here until the start of the Maui. For now let’s just focus on the two biggies: three-point percentage (3P%) and three-point rate (3PR, the percentage of a team’s field goal attempts that come from behind the arc).
It’s important to note that a million factors affect both of these numbers in any given game or set of games. How many threes are taken and made is partially a function of the defense, the venue, the score of the game, what the players ate for breakfast…you get the idea. Since I’m just one guy, I just looked at these two numbers for all offenses in both the regular season (including conference tournaments) and in the NIT.
Let’s start with the basics.
We can clearly see that teams made less threes in the NIT the last two seasons. Teams took less threes in 2018 as well, but last year the three-point rate remained about the same in the NIT.
But what if the teams that made the NIT in one or both of these years were worse than average teams at shooting threes? What if they were better? Let’s do it again with the regular season stats from just the 32 NIT teams.
The gap between regular season shooting and NIT shooting is actually even bigger when we look at just the regular season stats from the 32 NIT teams. Of course, shooting in the NIT in general is not necessarily going to be the same as regular-season shooting. It is well-documented that percentages go up throughout the year as players shake off the rust, so the NIT percentages probably would be higher with no change in arc distance. Let’s include 2017 (the last NIT with the same three-point line as the regular season) as a control.
Granted, when dealing with 31-game tournaments the sample is small enough to include a lot of noise. But it looks nice, and isn’t that the only thing that really matters? We can see that 3P% and 3PR both went up in the 2017 NIT, and on the whole this increase is fairly typical if we include previous years. So when we look at 2018 and 2019 compared to 2017, we are really seeing a decrease in two quantities that would have been expected to go up. All the caveats considered, it seems like we can expect a slight dip in three-point rate and three-point percentage when the season kicks off in November.
The last time the three-point line moved back was the 08-09 season, and we saw the same thing then. Three-point shooting did go down for a while, but eventually it stabilized to a pre-08 level as players improved and coaches adjusted the offenses they ran. Three-point shooting varies so much from game to game that the effects might not be discernible by what announcers like to call the “eye test,” but it will be fascinating to watch how both offenses and defenses adapt to the added distance and spacing. There may be some growing pains early on, but I foresee teams figuring it out in the next couple of seasons.
