When it comes to throwing the red flag, some coaches are more careful than others.
The AFC East provides a representative cross section of how coaches handle challenging calls on the field.
The Buffalo Bills, for instance, have challenged the fewest calls in the NFL. But they've gotten both of them correct. Dick Jauron challenged one call before the Bills fired him. Interim coach Perry Fewell has disputed one call so far. Both were over overturned.
New England Patriots coach Bill Belichick is among the most inefficient challengers, wasting five timeouts. He ranks 29th among all coaches with a 17 percent success rate, one reversal on six challenges.
For perspective, the NFL average is 39.3 percent.
That's about where New York Jets rookie head coach Rex Ryan is. He has overturned 40 percent, two of his five challenges.
Miami Dolphins coach Tony Sparano is tied with former boss Wade Phillips as the most proficient among those with six or more challenges. They've each reversed four of six attempts (67 percent).