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Examining the 49ers pattern of second half collapses

In several games the 49ers have started strong, yet are blown out by the final whistle. What is behind the second half decline?

NFL: New Orleans Saints at San Francisco 49ers Kyle Terada-USA TODAY Sports

You know the 49ers’ game script by now. The team starts out fairly competitive, sometimes even building a lead. Then comes the third quarter, where the team is seemingly allergic to scoring, amassing a mean 13 points while allowing 61. By the 4th quarter the game is out of hand, or close to it, and the team is one game closer to ending 2016’s misery.

What explains the team’s inability to sustain performance for a full game?

Theory 1: The team is being out coached

The premise here is two fold: Chip Kelly’s offense is predictable, and the staff as a whole is not adjusting as the game progresses. Looking at the DVOA splits by quarter, there is a little evidence to support the idea that teams are figuring out the offense.

The defense seems to be up and down, so unless you’re going to argue that O’Neil is making third quarter adjustments but not fourth quarter adjustments this theory doesn’t hold up.

The offense does fall off a cliff, but putting this at the feet of second half adjustments over-values their effectiveness. Teams have a limited number of plays they include in their game plan. Brian Billick recommends about 20 to 30-percent more plays than you anticipate calling. Coaches don’t have their full 1,000 play repertoire to call from in every game.

When a coach makes adjustments they are usually pulling from the plays they put in their plan to begin with. It’s not as if a coach can change their plan entirely from one half to the next. Typically these adjustments are smaller in nature; enough to spring you for a play or two. That doesn’t account for the precipitous second half offensive decline.

Where I do think this theory has legs is in the predictability of Chip’s plays. Chip has several formation tells that were, in the past, hidden by tempo. Because NFL offenses can’t move as fast as college offenses, the defense has more time to recognize the tells.

While there’s not an easy way to quantify this, and there’s some anecdotal evidence supporting the theory, I don’t see this being the sole explanation. If anything, predictability comes from the game score, forcing the 49ers to become one-dimensional as they try to play catch-up.

Theory 2: The team gets tired

This theory is predicated on Chip Kelly’s offense. Kelly runs so many more plays that his teams get tired and fade late in games. This is the easiest of the theories to dismiss. Kelly’s defenses in Philadelphia actually performed better in the second half of games, and late in seasons.

For the defense to decline in the second half, you would expect an outsized number of plays in the first half. However, the 49ers defense is only seeing an average of 5 more plays per game in the first half than NFL average. An extra five plays is simply not enough to tire a set of elite athletes into submission.

Theory 3: The 49ers have a terrible roster

Sometimes the obvious explanation is the right one. The 49ers simply do not have the talent to hang with even below-average NFL teams. On defense, the 49ers are starting a pair of backup inside linebackers that have no business seeing the field outside of special teams. Even one competent player could make a difference, and the 49ers don’t have many of them.

Even if you do have competent players they sometimes just miss basic assignments. Against the Saints, Quinton Dial slanted the wrong way and left a playside gap wide open, resulting in a Mark Ingram 75-yard touchdown.

On offense Colin Kaepernick is improving, but still suffers from accuracy issues. The wide receiving corps is easily the worst in football, with their top receiving “threat” ranking 72nd in the NFL. Vance McDonald just dropped another pass (DRINK!), while the offensive line ranks above only the Vikings in adjusted line yards.


The fact that this team approaches competence in any category is a testament to the coaches. Through week eight the 49ers rank 9th in red zone touchdown percentage. Their first quarter DVOA, when the team is working more closely off the coach’s script, places them 8th in the NFL. Coaching lifts the team up, then the talent level is exposed as the game progresses.

The defense, on the other hand, is a hot mess. They are not seeing any benefits from good coaching. Eric Mangini was able to get more run defense out of mostly the same stable of players. When you have inferior talent and inferior coaching you’re not going to hold up over 60-minutes of football.

Occam’s razor strikes again.