Brian Cook of mgoblog put up some photos from last week’s game between Michigan and Indiana, where Michigan pulled out the victory but Indiana’s Ben Chappell threw for 480 yards and three TDs, by completing over 70% of his passes. Most of these yards came from underneath throws, but Chappell hit a few big plays, including a big gainer on third and 16. Brian put up the photo below, followed by much hand-wringing:
Indiana uses the snag route concept to break a man wide open (shown below), and the question arises as to who to blame and if players were out of position. The above photo, however, shows most of what you need to see: you’re probably in trouble. It’s a wide trips bunch (trips but detached from the formation), the corner isn’t in position to get a jam, and you’re outnumbered. Being third and 16 it’s not a given that Indiana could convert, but this defense is not well equipped for the formation. To illustrate, let me flip the question around: If you were IU’s quarterback or offensive coordinator (or if you were Michigan and IU lined up like this against you), what would you call? The answer, most coaches would agree, is most anything you like, especially with the techniques Michigan used.
This works because of numbers: there are three receivers against two short defenders; the deep safety is not in position to tackle the bubble for a short gain. (And if he is, you use the fake-bubble and go play.) But it was third and 16 so you need to find a way to get the ball down field, or at least give yourself a chance to do so. Indiana called the “snag” concept. The purpose here is to form a triangle read, which is formed by combining a two-man “vertical stretch, i.e. one guy high and one guy low, and a two-man “horizontal stretch,” i.e. one guy outside and one guy inside. As shown in the image, the corner route and the flat route form the high/low portion of the read, while the flat also forms part of the horizontal or out/in stretch, with the slant-sit or snag route forming the other part.
On the actual play, the corner sat on the flat route and the corner route — one on one with the safety who had no help to either the inside or outside, and thus had little chance to make a play — was wide open.
This worked for the same reason the bubble screen worked: the cornerback (one guy) can’t guard two guys (the corner route and the flat route). But let’s say IU wanted to be more aggressive and wanted to attack more than just the corner; let’s say they wanted to put pressure — and get a numbers advantage — against both the cornerback and the safeties. How would they do that? With the trusty smash concept with the divide route.
We all know why Cover Two is called Cover Two: It’s because there are two deep safeties. Thus if you want to break someone downfield, you need to send three guys deep. The great thing about the smash is that you can outnumber the secondary both horizontally across the field (three guys running deep and stretching two deep safeties) but also vertically (high/low of the cornerback).
From bunch, the outside receiver widens on his hitch route to get the corner to widen and then simply breaks down. The backside safety is occupied by the backside split end going deep, and, as a result, the trips side safety has to make a very unfortunate choice between one receiver breaking for the post and another breaking for the corner. (Tampa Two refers to a variation of Cover Two where the middle linebacker drops back to cover the middle of the field; if they use this your speedy receiver might still beat him down the middle, but if not you have the runningback on a checkdown over the middle.) I’d say that if you play Cover Two against trips (which can definitely be done — more on that later), the first thing an opposing coach will try you with is the smash with a divide or seam/post right down the middle.
Now let’s say you are confident that you won’t get much pressure on your passer, and you want to hit a downfield pass, high/low reads be damned. In that case you pick the most aggressive horizontal stretch of them all, four verticals.