EDIT: Below I calculated the Win Value of a Net Forward Yard as 0.008. I was confusing it with the point value of a Net Forward Yard (which isn’t 0.008, but 0.08, so I was wrong in my memory, too). In fact, the Win Value of a Net Forward Yard is only 0.002. So each of the numbers in the chart should be only a quarter of the value listed, but it doesn’t change the ranking.
To get a different perspective on the impact each NFL Quarterback has had on the number of wins his team has produced, I took the statistical information about the value of forward yardage and the formulas provided in the the book Stumbling on Wins (written by Professor David Berri), but applied them only to those yards that each QB directly produced.
In other words, my Modified QB Win Score metric is basically the same as Professor David Berri’s QB Score, except it only credits each Quarterback for the “Air Yards” he produces through his passing (whereas QB Score credits all yards passing), and it only debits him for 1/11th the cost of every offensive play (-2.75 yards) he is on the field (whereas QB Score debits each QB the full amount for every play he is involved in, so to speak) (note: the cost in yards for each play comes straight from Berri’s work outlined in Stumbling on Wins). Also, unlike QB Score (but like Berri’s QB Wins Produced) I then multiply the resulting Total Yards Produced by 0.008, which is the win value of a net yard in football (once again using the win value of a yard produced calculated by Professor Berri and outlined in Stumbling on Wins). (Note: the reason I debit the QB 1/11th the cost of every play for which he is on the field is simple. Unlike Professor Berri’s QB Score, when a QB is involved in a play, I don’t give the QB credit for the entire result of the play, only for the result I can directly trace to him. Therefore, to be logically consistent, I cannot debit him the entire cost “his plays”, but I must debit him an equal share of the cost of each play he is on the field).
So, the formula for Modified QB Win Score is (Yards passing – YAC + Yards Running – Sack Yards – 30*AllQBTurnovers – 0.25*All Plays QB on Field) * 0.008.
Now, you could argue that some of those “Air Yards” I credit as “pure” Quarterback Produced Yards do not actually belong to the QB and should instead go to his linemen (for preventing a sack) and the targeted receiver (for securing the catch). Probably true, but the receiver’s share for the act of securing the ball would only be something like 10% at best, and I think the linemen’s share of yards are taken back from the QB by debiting him the entire amount of all sack yards lost (which yards are probably largely resulting from the missed assignments of particular linemen). Another slight problem with this metric is that it doesn’t reward passing efficiency as well as I would like it to. ( a more sophisticated approach might be to debit the Quarterback the full yardage cost of the plays in which he throws an incompletion, on the grounds that he is largely accountable for the plays failure. I will try to incorporate that next time. My guess is that it would not radically alter the relative results found below).
But with all that said, the metric does a good job of answering the question that I asked. I asked for a relative measurement of the impact on wins each QB is having on his team according to the actual yards being produced by the QB, after accounting for turnovers and sacks (the actual “wins” produced are probably a function of the amount each QB is above the overall average of 1.16).
I guess the main thing I wanted to do was separate each QB from his wide receivers. I think MQBWS does an excellent job of that, and the results listed below provide some fascinating insights.
Modified QB Win Score Rankings
Brady and Newton dominant, Roethlisberger not so much
The results included some surprises. For one thing, the much maligned Chad Henne ranked very high. For another thing, the much praised Ben Roethlisberger and Phillip Rivers ranked very low. Henne ranked very high because he has produced a very high amount of “Air Yards” (321 yards) and rushing yards (85 yards) while not turning the ball over too much (-60 yards) or being sacked too often (-43 yards). Roethlisberger also has a lot of “Air Yards” (331 yards), but he has a lot of turnovers (-150 yards), virtually no rushing yards (17 yards) and some sack yards (-50 yards). Mostly the turnovers have killed him. Same thing with Phillip Rivers. He has almost the exact same statistics as Roethlisberger, and nearly the same MQBWS.
On the other hand, some rankings were unsurprising. Tom Brady and Cam Newton rank at the very top. Each of them has produced a ton of “Air Yards” and Newton has rushed the ball well, which has offset his turnovers. On the flip side, Rex Grossman, a quarterback who looks great on some metrics, looks terrible here. Why? He has a decent amount of “Air Yards” (263), but he’s turned the ball over three times and he’s lost 55 yards in sacks, and he’s rushed the ball for only (-5) yards.
Two others that look terrible by MQBWS are Chicago’s Jay Cutler (0.54) and Atlanta’s Matty “Ice” Ryan (0.54). Those two are supposedly elite QBs, but each has an MQBWS that ranks above only the dreadful foursome of Tarvaris Jackson, Todd Collins of Indianapolis, Luke McOwn of Jacksonville, and Matt Cassell of Kansas City.
Sam Bradford and Josh Freeman generally fair better by the MQBWS standard than they do by other metrics. Each passes for a good deal of “Air Yards”. Neither seems to benefit a whole lot from YAC. Another guy who does better under MQBWS is Mark Sanchez of the Jets. Sanchez has alot of Air Yardage (298 yards) while minimizing the sack losses (-20 yards). He would look even better if he could cut down on the lost yards caused by turnovers (-120 yards).