Grossman's Game-Clinching Drive

The Redskins stunned the Giants on Sunday, winning 28-14 after shutting out Coughlin and crew in the second half.  After a Rex Grossman fumble to start the 4th quarter, the Redskins blocked a 38-yard Lawrence Tynes field goal attempt and the momentum swung in their favor.  Starting from their own 30, Washington went on a 6-minute, 10-play drive, culminating in a game-clinching touchdown pass to Jabar Gaffney.

Using a Markov model of a football drive, we can calculate the probability of a drive ending in any possible way: TD, field goal, turnover, punt, etc...

Here is a look at the Redskins final scoring drive:

The biggest play of the drive? Play 4.  Backed into a 3rd-and-9 on their own 45, Grossman completes a 7-yard pass to Fred Davis - short of the first down.  Enter Antrel Rolle: a 15-yard unnecessary roughness penalty keeps the drive alive and vastly shifts the probabilities.  Before the penalty, there was over a 60% probability the drive would end in a punt and only a 12% chance of a TD.  After the penalty, the punt probability drops to 5% and TD probability jumps to 37%.

The Redskins converted three 3rd-downs on the drive (plays 4, 7 and 10), ultimately scoring on a 3rd-and-4.  We see these 3rd-downs highlighted in the expected points:
Note: These expected points are based on the probability of scoring on one drive.  This expected points model differs from Brian's expected points model in a few ways, the most notable of which is that it does not include the interaction between drives.

Keith Goldner is the creator of Drive-By Football, and Chief Analyst at numberFire.com - The leading fantasy sports analytics platform. 

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3 Responses to “Grossman's Game-Clinching Drive”

  1. Anonymous says:

    Keith,
    Do you have a Markov model for drives of the last ten years broken down by yard line?

    I'd be interested to know where on the field punting drops off, where field goals and touchdowns are equal, and where field goals drop off.

  2. Keith Goldner says:

    It is separated into states based on Yardline, Down, and Distance. You can play around with it here: https://docs.google.com/spreadsheet/ccc?authkey=CNWl2cUF&key=0Ag6b9q23rVNDdGUyQU0xVTJiUnRqbXNFV3pWVjZmaEE&hl=en&authkey=CNWl2cUF#gid=1

    On 1st down, punting drops pretty steadily. On 4th down punting drops precipitously between 30-35.

  3. Dave says:

    Brilliant chart! All you need is to overlay the play by play or situation data (IE, their punt odds were highest when it was 3rd down, the penalty by Antrelle Rolle totally saved the drive) and you'd really have something.

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