The Red Raiders and Horned Frogs are among five Big 12 teams allowing fewer than 18 points per game.
It's no surprise that league leader Kansas State (6-0, 3-0) is also on that list.
The Wildcats have allowed just 21 points in their last six quarters.
After shutting out rival Kansas in the second half of a 56-16 thrashing, Kansas State held Iowa State to just seven points in the second half on Saturday and stuffed the Cyclones on fourth-down tries twice in the final five minutes.
Kansas State also held the ball for more than 40 minutes against Iowa State. Such a discrepancy in time of possession might be the key to slowing down Heisman Trophy hopeful Smith and the Mountaineers when they host the Wildcats this weekend.
"Their offense was productive as well, and consequently West Virginia didn't get its hands on the ball as much as they had in previous ballgames," Kansas State Coach Bill Snyder said about Texas Tech's performance against West Virginia.
Oklahoma fell off the national radar a bit after it lost at home to Kansas State a few weeks back. The Sooners seem to have sorted things out in part because of a defense strengthened by the arrival of defensive coordinator Mike Stoops.
Oklahoma (4-1, 2-1) allowed just 20 and 21 points respectively in wins over Tech and Texas, and that includes three touchdowns let up by the Sooners backups in garbage time.
"It's been our belief that you don't play good defense by trying to fool people or trying to blitz," Oklahoma Coach Bob Stoops said. "We pick our times when we do change up or blitz or what not. But we're counting on our technique and our fundamentals and playing good solid defense to win for us."
West Virginia has put up some dizzying numbers, but there was always going to come a day when the Mountaineers would need to lean on their defense. It came Saturday - and West Virginia let up 676 yards.
"I don't think anybody across the country in the history of football is able to put up the kind of numbers that we were on a very, very, very consistent basis," Coach Dana Holgorsen said. "We've got to be able to win some games on other areas of the field as well, such as special teams and defense."