The Buffalo Bills controlled their 38-3 win over the New York Jets very well on Monday, but for about ten seconds at the end of the first half, it looked like they were about to make one of their patented mistakes and re-energize the Jets right before halftime.
Fortunately for Buffalo, the wide-open Eric Decker wasn't able to pull in what could have been an easy touchdown pass, and the Jets ended up harmlessly running out the clock instead of pulling to within four points at halftime.
A favorite whipping boy of the fan base, third-year cornerback Stephon Gilmore was the "burned" cornerback in this scenario - but a closer look at the film shows that he wasn't at fault. Let's take a look.
The Bills appear to be lined up in a Cover 3 at the beginning of the play. There's a single deep safety (Aaron Williams), and both Corey Graham (jersey 20 at the bottom of the screen) and Gilmore (24, top of the screen) are in zone alignments. In a Cover 3, the cornerbacks set up in a deep zone toward each sideline, and a safety covers the deep middle of the field. This leaves the short patterns to the strong safety and the linebackers.
After the snap, however, Duke Williams drops back, showing the true coverage - it's a Cover 2. There are two safeties deep, each responsible for one half of the deep part of the field, and Graham and Gilmore are supposed to sit on the shorter patterns and try to break up a pass, if one comes their way. The disguised coverage alters the perception, from the observer's perspective, of what the cornerbacks' duties were on the play.
The Jets sent the two outside receivers on go routes, which should be a fine situation for a Cover 2. The safeties will already be aligned to cover the deep outside part of the field where those routes are targeted. There's also Jeremy Kerley, the Jets' slot receiver, running a square-in pattern across the middle of the field, and Chris Ivory is available for a running back dump-off if necessary.
At this point in the play, the cornerbacks are starting to separate from the guys who are leaving their zones. Graham is eyeing Kerley coming his way, and wants to pick up that route, so he hands off the coverage on the go route to Duke Williams. Gilmore doesn't have anyone in his immediate vicinity, but he needs to sit on the zone in case Ivory gets the pass, so he passes off to Aaron Williams. The only problem is that Aaron Williams is also focused on Kerley, and his body is not aligned to start moving toward Decker.
Finally, the safety starts to move toward Decker, but he's not nearly close enough. If this pass were thrown on target and in stride, it's a touchdown. Compare the positioning on the top of the picture to the safety's positioning on the bottom go route. Gilmore was about to drop down into his zone, but he looked, saw that his teammate was out of position, and started trying to play catch-up.
Here's the endzone view so you can see how open Decker was, especially compared to the other go route. It looked bad for Gilmore upon first viewing, but by looking more closely at the film, it appears that he played the role he was supposed to, and didn't get the safety help he was expecting. Fortunately for Buffalo, the Jets aren't the type of team to seize those opportunities every time.