Eighty-five percent of Adrian Peterson apparently is better than 100 percent of any running back in Oklahoma’s illustrious football history.

Peterson gained 210 second-half yards on the ground Saturday in OU’s 42-14 victory over Oklahoma State, which set a new program mark for most rushing yards in a half. Heisman Trophy winner Billy Sims had held the previous mark of 206 since 1979.

The Palestine, Texas, sophomore got most of those yards on explosive touchdown runs of 84 and 71 yards that surely will become part of Bedlam lore. Peterson finished the game with 237 rushing yards, which gives him 1,024 for the season.

For last year’s Heisman runner-up, the game was a triumphant ending to what had been a frustrating, injury-plagued regular season. Peterson suffered a high ankle sprain Oct. 1 against Kansas State, and the injury caused him to miss one game and be ineffective in two others.

Even with Saturday’s dominating performance, Peterson said his ankle still isn’t 100 percent healthy. When asked for a percentage, he furrowed his brow, thought, lightly moved his leg and uttered, “I’d say probably 85 percent.”

Peterson credited the blocking up front for his record-breaking second half.

“The guys on the line were doing a great job,” he said. “It was me being patient and letting things develop.”

Both touchdown runs came on the first play of OU possessions. When the Sooners took possession on their own 16 late in the third quarter, the offensive line opened the right side like Moses parting the Red Sea. Peterson burst through to the promised land 84 yards away, laying waste to a couple would-be tacklers along the way.

“The hole was too big,” he said. “I hit it like I was in track, running the 100.”

That touchdown, with 2:03 left in the quarter, opened OU’s lead to 28-7, and it proved big because OSU answered with its own touchdown early in the final period.

But Peterson all but sealed the game 17 seconds later when he found another gaping hole, this time on the left side, and scored on the 71-yard run with 11:20 remaining.

OU coach Bob Stoops said, “A.D. was just incredible” and that “he’s getting better and better all the time.” He wasn’t surprised, though, by the speed, strength and agility his young back showed Saturday.

“I shake my head at practice, I can’t tell you how many times,” he said.

The OSU defense stymied Peterson in the first half, holding him to just 27 yards on 11 carries.

The first quarter was worse: 8 yards on eight tries.