Ring Probability Added

by Joe Harris
When arguing a QB's "greatness" people often quote the number of rings a player has as a definitive conclusion to a debate. For example, Dilfer is obviously greater than Marino because he has a ring. And there is nothing else to it. That statement takes the logic a bit further than most people would, but that is essentially how a lot of fans view the world. Whilst I am not a fan of this form of logic, I thought that it would be interesting to look at this concept through the lens of WPA or, more specically, RPA - Ring Probability Added.

Ring Probability Added
The basic idea is to take Brian's WPA stats and weight it depending on the magnitude of the game. For example, in 2004 when New England beat Carolina, Tom Brady essentially did enough to win the game single-handedly with +0.97 WPA. This corresponds to +0.49 RPA - he increased New England's chances of winning the Superbowl by 49%.

The game magnitudes I assigned were:

Superbowl: 50%

Conference Championship: 25%

Divisional Round: 12.5%

Wild Card Round: 6.25%

Regular Season Game: 0.4%

The logic behind the Regular Season weighting was that I wanted to keep all the games equal. So I used a weighting of 1/256 (the number of games in a season). What this doesn't do is account for the fact that, when it comes to winning a Superbowl, 0 wins for the season is just as useful as 6 wins - either way your team misses the playoffs. But in the end the regular season had very little impact on the final results.
I thought it would also be fun to think about the Total Rings a player wins for himself and his teammates. Based on the assumption of 53 players on an NFL roster, I multiply the RPA by 53. Using this logic I conclude that in Brady's career he has won 73 rings for himself and his teammates.

It should go without saying that every QBs RPA is extremely dependent on the performance of the O-line and receivers in the same games.

The Results
The results are not hugely surprising. Brady leads the way with +1.38 RPA, followed by the Manning brothers, Roethlisberger and Brees - the winners of 5 of the last 6 Superbowls.

My favourite result is that Rex Grossman managed to total -0.38 RPA or -20 Total Rings in just one season. This is amazing but it is really a testament to that Bears defence; Not only did he play badly enough to lose each playoff game, the rest of the team bailed him out just enough that he had a chance to further hurt their chances in the next round.

Rank	Name	RPA	Total Rings
1	T. Brady	+1.38	73
2	P.Manning	+0.75	40
3	B.Roethlisberger	+0.57	30
4	E.Manning	+0.56	30
5	D.Brees	+0.52	27
6	K.Warner	+0.49	26
7	J.Delhomme	+0.30	16
8	A.Rodgers	+0.27	14
9	D.Culpepper	+0.16	9
10	S.McNair	+0.16	8
11	M.Sanchez	+0.15	8
12	M.Bulger	+0.12	6
13	J.Garcia	+0.09	5
14	P.Rivers	+0.08	4
15	B.Johnson	+0.08	4
145	J.Flacco	-0.11	-6
146	T.Dilfer	-0.12	-6
147	R.Gannon	-0.14	-7
148	K.Collins	-0.23	-12
149	R.Grossman	-0.37	-20

Some Final Thoughts
When I started this analysis I was hoping that the results would show Peyton in a more favourable light. Whilst I obviously wasn't expecting him to outperform Tom Brady, I did think that he would do slightly better vs Eli and Big Ben. However, if you account for the number of seasons each QB has played all three QBs have just over 3.5 RPA per season.

For good quarterbacks, having a good defence and running game is still very important when it comes to accumulating RPA. The chart below shows that Peyton has actual done more to get his teams to Superbowls than Tom Brady. Unfortunately for him this only translated to 2 Superbowls in real life vs Brady's 5.

(click on the chart for a larger, clearer version.)


Conversely, for bad quarterbacks, it can be better to have a bad defence - as highlighted by Rex Grossman who otherwise would never have been in a position to post such terrible stats in big games.