LAWRENCE — During most Kansas practices, the Jayhawks’ scout team specializes in running “shell,” the bare-bones motion offense that involves passing, screening and cutting.

It’s simple stuff, really, perhaps the most basic team defensive drill in basketball. But it may shed a little light onto one of the more peculiar stats of the early season. The KU defense, it seems, is stifling opponents and turning teams into unapologetic three-point chuckers.

The Jayhawks’ last three opponents all shot more than 30 three-pointers, and KU is holding opponents to just 24 percent shooting from three-point range during its last four games. Take a step back, and it becomes clearer: The defensive numbers have helped the sixth-ranked Jayhawks climb the polls during a nine-game winning streak.

“This year’s team,” Self says, “has done a really good job so far of everybody putting both feet in the circle and saying: ‘OK, let’s do this together.’ And that’s kind of refreshing.”

There are a few theories for the crazy three-point numbers. And it’s starts back with the “shell” drill. Self’s teams tend to have some of the most disciplined defenses in the country, following the shell tenets to the letter of the drill. The Jayhawks pressure the passing lane. They help on the weak side. They make it very difficult to score inside.

Of course, they also have senior center Jeff Withey, who can be a pretty nice deterrent in the paint.

“It’s intimidating,” senior guard Elijah Johnson said. “Nobody wants their shot blocked, I don’t care who it is. So you think twice about going in there.”

Self, meanwhile, has some other ideas. The Jayhawks have played three straight teams that shoot a lot of three-pointers, he says, and KU hasn’t done a good enough job of pressuring out on the perimeter. KU’s opponents may be shooting a low percentage, but that’s mostly because they’ve just been missing.

“I think in large part, our three-point percentage defense was one of the worst in the country the first seven or eight games of the season,” Self said. “It was awful. But the last few games it’s gotten better. But I think it’s in large part because teams missed.”

The theories will be tested again at 7 p.m. Saturday, when KU returns to the floor against American at Allen Fieldhouse. It’s Kansas’ first game since procuring a statement victory at Ohio State last Saturday.

And if the Jayhawks are benefiting from some poor shooting performances, the numbers still suggest they’re doing plenty of things right. KU ranks 12th in the country in field-goal percentage defense — and second nationally in defensive efficiency, according to college basketball analyst Ken Pomeroy, who specializes in advanced metrics.

“For us to be any good this year,” Self said, “we gotta hang our hat on that end.”

This is hardly new around Lawrence. Kansas has ranked in the top 10 nationally in field-goal percentage in eight of the last nine years. And this year’s team — with length on the perimeter and Withey inside — proved its chops against a talented Ohio State offense.

Self isn’t ready to rank this KU defense next to some of his best. But the presence of Withey certainly changes the equation.

“I think we’ve had some better defensive teams than this one,” Self said, “But I don’t think we’ve ever had a guy that can make up for mistakes like we have now.”

If KU is great at anything, though, Self says it may be playing together. Kansas has spent the last month breaking down opponents on defense, and the victories have followed. Aside from a five-minute stretch during the Ohio State game, KU has been in cruise control for weeks. And for Self, as his team prepares for conference season, this is both encouraging and alarming.

“I think there’s a point and time in every season, where a team becomes a team,” Self said. “And I don’t know if we’ve come to that point yet or not. Usually that happens through adversity, and we really haven’t dealt with much adversity yet.

“No coach wants to deal with it. But when you do deal with it, you’re usually better because of it.”