They rebound, and they don't let teams get to the free throw line.
By a lot of conventional means, Utah State is an average defensive team. They allow 41.3 percent shooting from the field (No. 113 in NCAA) and 33.3 percent from the 3-point line (No. 172). They're one of the dead last teams in steals, forcing only 4.9 per game (No. 324).
In advanced measurements, they're not tremendous, either. According to KenPom.com, they allow an average effective field goal percentage, which is a measurement that gives more weight to 3-pointers. They cause turnovers on only 15.9 percent of their possessions, which is only No. 335 in the NCAA.
But there's two ways to think of defense: One is by forcing opponents into bad, poorly made shots, and the other is to limit opportunities to shoot. In this second respect, Utah State is a high-performing team.
This is somewhat explained by USU's plus-9.1 rebounding margin, but statheads such as Ken Pomeroy don't like rebounding margin because defensive rebounding and offensive rebounding are very loosely corrolated.
Consider, instead, that the Aggies lead the conference in defensive rebounding percent, getting defensive boards 73.9 percent of their chances in WAC play. Although that figure was partially assembled when Reed and Medlin were healthy, defensive rebounding has undoubtedly been a factor in the last three games.
Against Idaho, Seattle and San Jose State, the Aggies had a defensive rebounding rate of 83 percent. More than four times out of five, those teams didn't have another chance to shoot the ball after a miss. By comparison, those teams had a collective 64.9 defensive rebounding percentage against the Aggies, giving Utah State an extra chance on more than one-third of its misses.
This figure helps explain why Utah State can win a game even when a team like Idaho shoots 53.6 percent from the field.
Jarred Shaw leads the team in defensive rebounds, but obviously Spencer Butterfield and Ben Clifford have also been a huge factor in helping get those boards in recent weeks. Butterfield has said in several post-game interviews that the big men have helped him get free inside by boxing their men out. Not every team sends three guys in for boards, so Butterfield can exploit that mismatch in the paint when the scrum is going for the bounce.
The other factor is free throw shooting, or lack thereof. Utah State gives up only 15.4 fouls per game, the 33rd-fewest in the NCAA. Kenpom.com lists Utah State's attempted free throws-to-attempted field goals as only 24.8 percent in conference play, which leads the WAC.
What it means is Utah State doesn't allow teams to get a lot of their points on the charity stripe. In the three victories, the Aggies had only 22 free throw attempts taken against them. That was a big key in the defeat to UT-Arlington, in which the Aggies allowed 34 free throw attempts.
Utah State nearly beat Louisiana Tech by rebounding well and only letting the Bulldogs take seven free throw attempts. Obviously, the officials play a large part in the free throw line appearances, but the Aggies have done a superb job of limiting contact while still playing good defense.
There are always factors that can't be measured by numbers, but you can bet those numbers have helped Utah State a lot in their recent run on the road. And if the Aggies are to keep winning, that's how they'll have to do it.
Kyle Goonkgoon@sltrib.comTwitter: @kylegoon