Sean McDermott is taking a no-stone-unturned approach to coaching challenges this offseason.
McDermott's challenges were not a particularly big issue in 2017. The Buffalo Bills did not encounter as many controversial challenge situations as some teams.
McDermott challenged only four plays, and one of those was overturned in his favor. Only four teams made fewer coaching challenges than the Bills. The average was 5.7 per team.
Yet McDermott cites challenges as one of many things he's looking more closely at after his rookie season as an NFL head coach.
"There were some that I thought were on point, and there were some where I thought I could have done a better job," McDermott said. "And so that's a big deal. You just try to learn from every situation and take that type of approach."
"I've spent a lot of time here, the combine as well, talking to a lot of the veteran coaches, trying to take that opportunity, 'Hey, how do you do this? What's the best way to do that?' " McDermott said at the NFL owners meetings. "I don't think anybody has a perfect way to practice those situations, other than just get into a simulated deal in your office. That's what we do with our staff. I count on our staff on some of that."
NFL coaches succeeded in getting a reversal of a call on 47.3 percent of their challenges in 2017, according to the website Football Zebras. On plays subject to automatic review, such as process-of-the-catch situations, scoring plays and turnovers, the centralized NFL replay office overturned the calls on 44.5 percent.
McDermott's one replay win was significant. In the 26-16 home win over Denver, McDermott challenged that a 44-yard Broncos pass play was not a catch. The call was overturned. The Broncos were forced to punt from deep in their territory, and the Bills turned the sequence into a key field goal.
A wasted McDermott challenge came in the home loss to New England when the Bills contested that Tom Brady was down before throwing a pass, even though it appeared obvious Brady was knocked down by a teammate before getting up and making the throw.
The most successful: Detroit's Jim Cladwell was 4 of 5 on challenges. Cincinnati's Marvin Lewis was 5 of 7 and Minnesota's Mike Zimmer was 5 of 8. The success rate of coaches has been fairly consistent. It was 49.7 percent in 2016 and 45.8 percent in 2015.
Story topics: Sean McDermott