Tim Tebow isn't the only reason for Denver's surprising turnaround this season.
The Denver Broncos' playoff chances looked bleak after the first five weeks of the season. They were just 1-4 entering their bye week, including two losses to division foes (Oakland Raiders and San Diego Chargers).
Coach John Fox named Tim Tebow as his starting quarterback for their Week 7 matchup in Miami, and including that overtime win, the Broncos have now won six of seven games with Tebow as the starter and are currently on a five-game win streak.
Tebow has been the unflappable leader of the team on offense behind center, engineering four fourth-quarter comebacks this season despite a Total QBR of 36.3 that ranks 30th among qualifying quarterbacks in the NFL.
What is going on here? Tebow’s QBR implies that he’s a below average quarterback, but “all he does is win games.” Is QBR unable to account for Tebow’s magic or is there some other reason for the disconnect?
Lowest Total QBR in Wins as Starter
Tebow’s QBR in the Broncos’ six wins with him as a starter is just 43.0, showing that his play on the field is not the primary reason why they are winning. Remember, 50 is the average Total QBR and the cumulative Total QBR for all winning starting QB this season is 68.6.
We can take this analysis a step further by using the interpretation of Total QBR as an expected win percentage of the quarterback’s team.
Tebow’s average game-level QBR in his seven starts is 40.1. Across seven games, that should correspond to about 2.8 wins, or approximately a 3-4 record.
The Broncos have defied the odds, though, and are 6-1 with Tebow as a starter. In order to see how are they winning some of these games almost in spite of Tebow, we can use win probability to quantify the plays that had the largest impact on the Broncos’ chance of winning in each of his seven starts.
Tebow had the largest impact plays in wins against the Kansas City Chiefs and New York Jets, games in which he had solid Total QBR scores above 70. But in the four other wins, the biggest plays of the game took place with Tebow on the bench.
The defense made two huge game-changing plays, including Andre' Goodman's interception on Sunday and D.J. Williams' strip-sack in overtime vs the Miami Dolphins. The largest impact plays in the other two wins came on special teams via an Eddie Royal punt return touchdown (Week 9) and a missed field goal by the Chargers (Week 12).
Obviously Tebow has made some big plays not listed above to help his team win, but the point is that the defense, special teams, and mistakes by the opponent have also played a major role.
Total QBR sees all the plays that Tebow participated in and determines how much impact he had on his team in each of those plays in all of his games. When analyzing reasons for the Broncos’ 6-1 record with Tebow as starter, Tebow’s poor QBR indicates that we should look beyond him and praise other Broncos for their significant contributions to the team’s recent success.