## Wednesday, January 26, 2011

### Passing in the Post Season

by Denis O'Regan.

Using post season data and a logistic regression approach I've taken another look at how completion rates are dependent on how far a quarterback is throwing the ball in the air.

I've made the dependent variable the outcome of the pass attempt (1= a completion and 0= an incompletion) and used the position on the field where the ball is caught or not caught by the receiver as the independent variable. Yards after the catch is discounted if the pass is caught.

I've run regressions for Rivers, Roethlisberger, Brady, Rodgers and Manning, seperately pooling all their attempts in the post season since 2006. I've also included Rex Grossman as an example of a not particularly accurate QB and Mark Sanchez, whose completion rate appears to thrive in the post season and is on an upward career curve.

The results table includes the probability of each QB completing a pass that is thrown a certain number of yards from the line of scrimmage. I've started at five yards behind the line and then extended that deeper downfield in five yard increments. So for example a Manning pass that is thrown 20 yards downfield in the playoffs, has a 46% chance of being caught. A column for all post season QBs over the period is included to provide a baseline figure.

 Distance All QBs Brady Manning Rivers Roethlisberger Rogers Sanchez Grossman -5 0.75 0.85 0.86 0.60 0.80 0.85 0.79 0.63 0 0.70 0.78 0.81 0.60 0.76 0.81 0.74 0.61 5 0.63 0.69 0.74 0.60 0.69 0.76 0.67 0.58 10 0.57 0.59 0.65 0.50 0.62 0.70 0.61 0.56 15 0.50 0.48 0.56 0.50 0.53 0.64 0.53 0.53 20 0.43 0.37 0.46 0.50 0.45 0.57 0.46 0.51 25 0.37 0.28 0.36 0.40 0.37 0.49 0.38 0.48 30 0.30 0.20 0.27 0.40 0.29 0.42 0.31 0.46 35 0.25 0.14 0.20 0.40 0.23 0.35 0.25 0.43 40 0.20 0.09 0.14 0.30 0.17 0.29 0.20 0.41

I'll resist the temptation to overanalyse each players passing profile, but it's worth noting that Manning, Rodgers, Roethlisberger and Brady are all very accurate when passing within 5 or 10 yards either side of the line and it's this area where the vast majority of the balls are thrown to be caught. Sanchez is also above the baseline figure for all QBs in that region of the field, but Rivers' profile looks much more like that of Rex Grossman.

Tarr said...

Denis, where did you find the data this is based on?

Anonymous said...

Probably not enough data yet for Rivers....

Anonymous said...

What is the difference between all qbs in the regular season, and all qbs in the playoffs?

Bruce D. said...

Nice.

I see Manning here as the biggest difference maker on his team.

Something that was suspected, and here you've provided some actual proof.

Bruce