Twelve more inches to get the extra point
Posted by kj on Monday, June 23rd, 2008
SI.com’s Luke Winn has a good piece up looking at the probable impacts of the longer three-point line next season. The line is being moved back a foot–from 19′9″ to 20′9″. I thought we’d take a moment to speculate on how the rule change is likely to impact our Spartans.
The simplest way to look at this rule change is that it will almost certainly reduce three-point shooting percentages by at least a half a point or so, all things being equal. Team that shoot a lot of three-pointers, therefore, will suffer. And teams that don’t shoot many three-pointers should benefit.
Under that line of thinking, Mr. Winn predicts the deeper line will hurt a number of mid-majors (Butler being a prime example) that rely heavily on three-point shooting for scoring. And he thinks North Carolina and UConn–two teams likely to be in the title hunt next year–shouldn’t be affected much, as they relied on three-pointers for the lowest percentage of their scoring among the 65 teams in the most recent NCAA Tournament.
Similarly, we should expect Michigan State to be OK, as they had the 4th lowest percentage of points scored from beyond the arc among the 65 tournament teams. You’ll recall that MSU ranked in the bottom 10 nationally in the percentage of field goal attempts taken from 3-point range. With the loss of Neitzel–and the addition of Roe’s inside scoring abilities–there’s no reason to think that percentage is going to increase substantially next season.
On the defensive end, Winn points to Basketball Prospectus’ seminal work on shooting percentages by shot distance, which concluded that the best defenses force a lot of mid-range two points attempts.* Winn uses the percentage of points given up by a defense from three-point range as a proxy for the ability to force tough shots. I’m not sure that’s a great measure, since it could be a function of a team giving up too many easy baskets inside. (Note: I used the graph in the BP piece to come up with my highly scientific “half a point or so” estimate for the likely reduction in three-point shooting percentage with the deeper line.)
MSU allowed quite a few three-point shots last season–ranking 250th in the nation in the percentage of field goal attempts taken by their opponents from three-point range (the assumption in the rankings is that allowing more three-point shots is bad). But they ranked 21st in the nation in holding opponents’ three-point shooters to a 31.2% shooting percentage. If the Spartans can continue to force their opponents to take a lot of low-quality shots from three-point range, the longer line could benefit them on defense.
(Note: All of the MSU statistics listed above are pretty consistent with their numbers from the last several seasons, reflecting some basic tendencies of Izzo’s offensive and defensive systems.)
Finally, Winn notes that the longer line may hurt teams with a high number of “marginal” three-point shooters on the roster. This does concern me a bit as far as MSU’s shooters go. Lucas, Morgan, and Summers are all guys who shoot the three on occasion, but are more comfortable taking mid-range shots. Taking another step back may have a larger impact on their shooting percentages than it would on purer long-distance shooters like Neitzel and Allen.
Here’s the wild card I don’t think anyone can predict at this point:
The key question for both of them [Duke and UCLA] this season will be whether the extra foot that their defenses extend on the perimeter opens up too many easy scoring chances in the paint.
If defenses feel obligated to guard outside shooters, even the marginal ones, closely behind the longer line, that could provide extra room for post players to maneuver inside the paint. This would be good for a team with a front line of Raymar Morgan, Delvon Roe, and Goran Suton.
On the other end of the court, playing Izzo’s man-to-man defense with an emphasis on help defense will require that much more hustle in getting back to cover outside shooters. Of course, this will also be true for teams that play a zone defense, with defenders required to cover a slightly larger area within the half-court area.
All in all, this is relatively minor rule change, and I don’t see the longer three-point line as a big area of concern for MSU. It will be interesting to see whether the extra foot creates any perceptible statistical changes across college basketball.
*Mini-rant: Luke Winn’s work is among the best in the realm of national college basketball writing. And he’s a heavy user of tempo-free stats. So I have no particular gripe with him.
But allow me to complain about this: While relying on Basketball Prospectus’ work to make one of his arguments, Winn’s article does not include a link to the BP piece. For as much some critics of the blogosphere cite the fact that bloggers ultimately rely on mainstream media sources for a lot of their material, you’d think Sports Illustrated could take the time to link to the Basketball Prospectus piece (which I still think of as being fairly bloglike) to allow SI.com’s readers to easily access it.
OK, mini-rant over.
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