From the FanPosts. -Joel
This is the third installment in what is becoming a series of offseason posts that will create a picture of what the 2012 season should look like for the Chiefs. First was a post on what we can expect from the Broncos now that they have Manning. Second was evaluating the Chiefs current QB situation and what that should look like. I think they'll start Cassel, but I explained why Quinn might be the better choice.
Today I'll be looking at one of the two remaining divisional opponents. Division opponents are very important in the NFL. The quality of your division can mean the difference between being the top seed in the playoffs and missing them altogether. I think our division will likely be a 3-team race between the Chiefs, Chargers, and Broncos. (Although last time I said our division was a 3-team race the 4th team ended up winning the division.)
The Chargers are an interesting team. Last year they had an unusually bad season, and many wondered if it was because Philip rivers was secretly playing injured. This post will be dedicated to testing that hypothesis, and after determining whether it's true or not, seeing how good the Chargers should be next year.
Was Rivers Injured?
I'm actually not going to answer that specific question. To me, finding out whether or not he had a uncharacteristically bad season is enough, whether or not it was due to injury. Either way, we would expect him to return to his normal form.
So, what is his normal form, and was he significantly below it in 2011? We'll look at both his traditional and advanced stats (if you're confused by some of the stats I use, they are explained at the bottom of my QB post linked above).
His WPA is actually pretty consistent in 2011, but I wouldn't put much stock into that because he was clearly worse in NY/A and EPA/P*. In fact, those latter two stats were significantly lower in 2011 than it had been for several seasons. I think it's safe to say that, for whatever reason, Rivers had a bad year, and chances are that he will be back to his normal form in 2012.
*(Note: EPA/P is expected points added per play. Basically, at any point in the game, you have a certain chance of scoring a touchdown, a certain chance of kicking a field goal, a certain chance of your opponent scoring a touchdown, etc. When you add all those factors together, you get the expected points for that situation. If your QB makes a play that increases your expected points, he has added expected points. When he makes a play that hurts your expected points, he gets negative expected points added. When you sum all those together, you get the total expected points added. EPA/P divides this by the number of plays so that you get a better idea of what they're doing on average.)
How Much Better Will They Be In 2012?
This is a tricky question. Since his WPA was consistent in 2011, we can do the approximation I used to determine how good the Broncos will be. However, it's possible to do a similar trick using EPA, it is just a little bit harder and uses something called the Pythagorean Theorem.
In sports, the Pythagorean Theorem is a formula used to estimate how good a team "really" is. It's named that because it looks similar to the Pythagorean Theorem that mathematicians use to find the hypotenuse of a triangle. It takes in how many points you scored (PF) and how many points were scored against you (PA) and determines what winning percentage you would expect to have. The exponent was determined by what number made the best predictions.
Since 2003, the chargers had double-digit Pythagorean wins except for 2011, where their Pythagorean record was 8.7-7.3. Still not bad, but clearly a decrease from what they have been the last decade. Since we have already determined that Rivers had an unusually bad year, we expect this is at least partially due to that. This also will allow us to estimate what the 2011 Chargers would have looked like had Rivers played at his normal level. We can do this using EPA.
Unfortunately, EPA doesn't tell us whether or not those points would go to offense or defense or both, which makes a difference in the formula. After running the numbers, it looks like it doesn't effect it all that much. No matter how you distribute the points, their Pythagorean wins, after adding in the 26 points Rivers would have added had he played at a normal level, go to about 9.3.
This is pretty far below their normal level, and thus we can conclude that their slide is due to more than a bad year by Rivers, and even if Rivers returns to his normal form, they will be about a 9-7 team.
In my Broncos post, I estimated them to be around 8 wins. Since these are both pretty rough estimates, I think it's safe to say that the Broncos and Chargers will be pretty close to each other when the dust has settled in the 2012 season. If the Chiefs can reach 10 wins, we have an excellent chance of winning the division.