Often when a team is ahead by a few scores in the second half, they’ll switch to a big play preventative defense like the aptly named ”Prevent." Typically this defensive set-up is aimed at keeping all plays underneath 10-15 yards and making the opposing team run out of gas while running out the clock.
The Prevent is accomplished mostly through “quarter coverage” where the defensive backfield is divided into four coverage zones and the secondary adjusts their coverage to match these zones. Cornerbacks play deeper off of receivers and have deep sideline zone coverage responsibility while the safeties guard two deep zones in the middle of the field. Instead of blitzing and putting pressure on the quarterback, the middle linebackers drop into zones to cover 5-10 yard slant, in, hook and shallow post routes. The outside linebackers’ responsibility become covering “the flats,” 5-10 yards deep on either side of the tackles to the sideline.
When in this defense, the goals are simple:
- Don’t give up the big play.
- Keep the ball in-bounds
- Be slow to let them up after you tackle them
- Have them run a lot of plays and tire themselves out running down the clock
When a team executes this type of defense, it can be very effective in closing out games. Unfortunately against the San Francisco 49ers, the Houston Texans had some trouble running the Prevent. Though they won the game, the Texans made it look like the game was closer than it was and gave their fans a slight worry that they'd blow another one by allowing two scores late in the game.
Generally it’s a good rule of thumb to go to the Prevent in the second half if you are ahead by three or more scores. It's safe and it runs down the clock. At the time that the Texans switched to it they were only ahead by two touchdowns, which was their first mistake. Until that point, the Texans defense was working very effective at keeping the 49ers out of the end zone with the exception of one play.
The Texans also went to the Prevent very early in the second half, which also helped in allowing the 49ers to climb back in to the game. However, switching to the Prevent too early and without enough cushion between scores wasn’t the determining factor in what lead to the 49ers making this a close game. The poor execution by the linebackers and safeties is what led to the two late deep touchdown passes.
Let’s face it: Alex Smith is a terrible NFL quarterback. He didn’t just “wake up” at halftime in a game halfway into his 5th season. The poor execution of the Prevent defense is the only reason the 49ers were able to crawl back into it. The majority of the fault has to do with the inexperience of Demeco Ryans, Brian Cushing and safety Bernard Pollard and their inability to communicate to one another mid-play to transition their zones to make sure that a tight end is covered as he moves from the 5-10 yard zone to the deep zone. This miscommunication led to Vernon Davis being wide open between the two zones on both big touchdown plays.
With 7 defenders dropping into pass coverage, the Prevent defense also lacks a pass rush. With very little pressure being put on him, even David Carr could’ve made the throws that Alex Smith made. So 49ers fan, I wouldn’t get your hopes up on Smith if I were you.
Truth of the matter is that if the Texans had stood by their game plan a little bit longer, they most likely would have maintained their lead. Part of the reason I think they went to the Prevent so early was in hopes of keeping everything underneath leaving the 49ers offense to run out the clock themselves. It’s a good strategy given the Texans inconsistent running game, but would have to have been executed better to be pulled off.
As we’ve learned thus far in 2009 though, the Texans defense is tremendously good at learning from mistakes and adjusting accordingly. I don’t see why this game would be any different. Expect the Texans defense to improve from this slip up and to come out strong against the pass in the coming weeks. A win is a win, but winning by a big margin would make the wins just taste even better.
After 7 weeks, I still stand strong in my belief that the Texans will have a winning season. With an ever improving defense with a lot of talent and an incredibly productive offense that has Matt Schaub leading the league in passing yards as well as touchdowns, the games should get progressively more and more fun to watch, ending in more wins than losses.
Ironically the 2009 Texans remind me a little of the 49ers from the Montana era. A really strong, high scoring offense that scores a lot of points with a young talented defense that is trying to put the puzzle pieces together to knock some blocks off. Andre Johnson favors the great Jerry Rice, while Steve Slaton (without fumbling issues) reminds me a little of Roger Craig. Owen Daniels is an easy comparison to Dwight Clark and hard hitting Vonta Leach packs the punch of a Tom Rathman.
Can Matt Schaub be close to being a leader like Montana? It’s still early in his career and only time will tell. Let’s start with posting another 300 yard, 3 touchdown win over Buffalo and we’ll go from there.