For this season, ESPN launched a new metric of measuring quarterbacks, called QBR. What exactly is QBR? A quick refresher:

QBR measures quarterbacks on a scale of 0 to 100, evaluating all plays they're involved in that contribute to victories. In other words, how a quarterback factors into wins. QBR factors in such components as where on the field a pass is completed and what the down-and-distance. A 3-yard pass on third-and-two counts for more than a 10-yard pass on third-and-20. Runs, sacks and penalties are also accounted for. And a month into the season, when there is enough information, the strength of the defense the quarterback facing will be factored in, too.

After Week 1, here are the QBRs (remember, the opposing defensive strength is not factored in yet) in the Big 12:

Bryce Petty, Baylor: 92.8 David Ash, Texas: 85.2 J.W. Walsh, Oklahoma State: 83.6 Baker Mayfield, Texas Tech: 78.5 Paul Millard, West Virginia: 62.7 Sam Richardson, Iowa State: 53.4 Jake Waters, Kansas State: 48.1 Casey Pachall, TCU: 45.2 Trevor Knight, Oklahoma: 42.9 Trevone Boykin, TCU: 20.4

A few thoughts and observations:

Even though Petty and Ash have the best QBRs, Mayfield had easily the top pass EPA (expected points added on pass attempts) with a score of 11.6. No other Big 12 quarterback had a score higher than a 6.1. What kept Mayfield’s overall QBR from topping the league were the four sacks he took in the SMU game. That underlines a major concern for Tech moving forward: offensive line. The Red Raiders didn’t run the ball well at all against SMU, either. It won’t be easy for Mayfield to continue to shine if he’s not protected better.

J.W. Walsh's rushing prowess was a big factor in his lofty QBR score in Week 1. AP Photo/Richard Carson While Mayfield had the best pass EPA, Walsh delivered the best run EPA, with a score more than double any other quarterback. That’s hardly surprising, as Walsh currently leads all players in the Big 12 in rushing. Yet for the Cowboys to reach their full potential offensively, Walsh will need to improve upon a pass EPA of 1.4.

Even though Pachall had only a marginally better QBR, TCU coach Gary Patterson elected to go with Boykin for most of the second half. Boykin had the worst Week 1 QBR among qualifying quarterbacks, though it should be noted Boykin’s QBR from the LSU game will look much better once defensive strength begins factoring into the equation. But neither quarterback really distinguished himself in the LSU game. This could be a quarterback controversy that lingers.

Knight’s first game numbers don’t look good through the QBR prism. He had the third-best run EPA behind Walsh and Richardson, but he actually had a negative pass EPA. Pachall was the only other quarterback with a negative pass EPA. Knight seemed to gain confidence with his arm as the game against Louisiana-Monroe wore on. But there’s no doubt Knight will have to be more precise with his passing if the Sooners are to win in South Bend, Ind., at the end of the month. Notre Dame’s Tommy Rees looked sharp in their opener, and has the seventh-best QBR (94.9) in the country.

QBR is useful in determining where quarterbacks struggled and where they succeeded in the first week. But the true value of the formula won’t come to fruition until opposing defensive strength is factored in later this month. It’s a safe bet that quarterbacks such as Boykin, Pachall and Walsh would have scored higher with that component; and others, like Petty and Ash, a bit lower.