This is the year of defense in the Big 12 Conference.

Five teams — the most since the conference started in 1996-97 — are allowing fewer than 63 points a game, and just two are giving up more than 70.

“Our league is guarding right now,” Kansas coach Bill Self said Monday. “Everybody puts an emphasis on getting stops.”

Nebraska started the week first in the league and fourth nationally with a defensive average of 56.5 points a game. No. 16 Texas A&M was allowing 58.7 points, and No. 3 Texas was giving up 60.5.

The Cornhuskers and Aggies met Saturday in Lincoln, and, predictably, defense decided Nebraska’s 57-48 victory. A&M scored 17 points in the second half, was held to two field goals over the last 9:50 and finished with its lowest point total of the season.

Tough defense also fueled third-ranked Texas’ 71-58 victory over Missouri in Austin. The Tigers, the highest-scoring team in the Big 12, were held 27 points below their season average. Texas held Missouri to season lows in points, field-goal percentage (33.9), three-point percentage (22.2) and assists (six).

“It is no secret how they play,” Missouri guard Kim English said. “They are a physical team, fast to the ball and big, strong guys.”

Baylor coach Scott Drew said defenses have become more sophisticated since he entered the Big 12 in 2003. No longer do teams rely so much on straight man-to-man schemes.

“Everybody has a different twist in what they do,” he said. “It might be doubling the post, switching, denying, more packed defense. It’s tough to prepare for every game because there is an adjustment.”

Last season, Kansas led the Big 12 with a 64.2-point defensive average, and five teams allowed 70 or more.

“I do think teams we’ve played defensively are better than they were last year across the board,” Texas A&M coach Mark Turgeon said. “It’s been very difficult to manufacture points and get easy shots.”

Strong defense has always been Nebraska’s calling card under Doc Sadler. The Huskers have consistently ranked in the top half of the Big 12 under Sadler in scoring defense. Two years ago the Huskers were the only team in the league to give up fewer than 65 points a game.

With Lance Jeter averaging almost two steals and Andre Almeida and Jorge Brian Diaz each blocking at least one shot a game, the Huskers (15-5, 3-3) already have matched their win total from a year ago and have won one more conference game.

The Huskers have held seven of their 20 opponents under 50 points and 12 under 40 percent shooting from the field. Only one opponent has shot better than 46 percent, and five have been below 30 percent.

Sadler said some teams can get away with lax defense because they’re so good offensively. That’s not the case with his Huskers, whose 68.8 point scoring average is second-to-last in the Big 12.

“We’ve sold the fact to our players that if you want a chance to be in most games, we have to defend,” Sadler said.

Texas (18-3, 6-0) has held its first 21 opponents to an average of 60.5 points on 36.6 percent shooting, including 27.8 percent from long range. The Longhorns’ first six Big 12 opponents have managed 54.2 points a game on a combined 36.9 percent shooting, including 20.5 percent on threes.

Tristan Thompson, a 6-foot-8 freshman, has been a force in the middle with his rebounding and ability to block shots with either hand. He leads the league with 2.19 blocks a game. The Longhorns’ perimeter defense, led by Jordan Hamilton, is one of the team’s most improved areas.

Texas assistant Russell Springmann said the players look out for one another on the defensive end.

“That’s something special when you get a group of guys who are willing to cover their man,” he said, “and one more.”

Texas A&M (17-3, 4-2) has limited nine opponents to under 38 percent shooting, and Khris Middleton, B.J. Holmes and Dash Harris are each averaging better than a steal a game.

“It’s the culture you set from the beginning,” Turgeon said. “They realize to be part of the team and rotation, they have to defend. You look around the league, and most teams coach that way.”