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.