As has been the case for nearly two months now, the steady decline of NFL offenses continued in week 13. Scoring has dropped from 24.8 points per game last year to 22.9 this year. The league is currently averaging 11.0 yards per completion; if this holds it will be the lowest in NFL history. There’s also been a marked shift in touchdown passes vs. interceptions. Early in the season there were 3.5 TD passes for every INT; that ratio is now below 2 to 1. For the first time in several years the NFL has found a nice equilibrium between offense and defense. It’ll be interesting to see if the competition committee devises rule changes to boost offense again in 2022.

Here are the week 13 rankings:

#	QB Week 13	Plays	PFF	QBR	zPlays	zPFF	zQBR	zAvg
1	Tom Brady	52	84.9	82.3	1.07	1.49	1.61	1.44
2	Tua Tagovailoa	46	89.1	65.9	0.46	1.79	0.93	1.27
3	Matthew Stafford	41	80.3	62.1	-0.06	1.15	0.77	0.79
4	Justin Herbert	42	71.9	79.9	0.04	0.53	1.51	0.73
5	Kirk Cousins	47	79.1	49.8	0.56	1.06	0.26	0.72
6	Gardner Minshew	33	72.1	78.3	-0.88	0.55	1.44	0.53
7	Ben Roethlisberger	35	75.3	64.3	-0.68	0.78	0.86	0.51
8	Joe Burrow	48	76.7	32.6	0.66	0.88	-0.46	0.44
9	Carson Wentz	28	69.9	83.9	-1.40	0.38	1.67	0.42
10	Taylor Heinicke	38	69.5	65.7	-0.37	0.36	0.92	0.38
11	Derek Carr	45	76.3	33.1	0.35	0.85	-0.44	0.37
12	Dak Prescott	45	67.2	38.2	0.35	0.19	-0.23	0.10
13	Zach Wilson	44	67.0	38.0	0.25	0.17	-0.23	0.07
14	Jimmy Garoppolo	35	73.6	32.9	-0.68	0.66	-0.45	0.06
15	Russell Wilson	46	66.5	30.8	0.46	0.14	-0.53	0.00
16	Jared Goff	48	59.1	45.5	0.66	-0.41	0.08	-0.05
17	Josh Allen	42	70.9	20.4	0.04	0.46	-0.97	-0.05
18	Andy Dalton	50	66.2	11.5	0.87	0.11	-1.34	-0.17
19	Taysom Hill	56	57.0	28.2	1.48	-0.56	-0.64	-0.18
20	Kyler Murray	29	51.7	85.4	-1.29	-0.95	1.74	-0.21
21	Matt Ryan	51	59.8	23.8	0.97	-0.36	-0.82	-0.23
22	Patrick Mahomes	34	61.4	44.3	-0.78	-0.24	0.03	-0.27
23	Lamar Jackson	59	44.2	42.5	1.79	-1.50	-0.05	-0.41
24	Trevor Lawrence	37	56.7	29.1	-0.47	-0.58	-0.60	-0.57
25	Teddy Bridgewater	48	44.1	25.5	0.66	-1.51	-0.75	-0.85
26	Mike Glennon	47	40.9	18.5	0.56	-1.74	-1.04	-1.07
27	Tyrod Taylor	20	42.5	2.7	-2.22	-1.63	-1.70	-1.77
28	Davis Mills	18	36.4	6.2	-2.42	-2.07	-1.56	-1.99

This week is notable for some major disagreement between PFF grades and QBR scores. The correlation between them is just 0.53 which is amazingly low for two metrics that are essentially trying to measure the same thing. For a pair of quarterbacks, their score divergence can mostly be attributed to something rather silly – the NFL’s antiquated method for assigning fumbles.

RANT TIME
Among the things that don’t affect game outcomes and mean nothing in the grand scheme of life, the NFL’s administrative nonsense around QB fumbles really grinds my gears. As FP readers likely know, all aborted snaps and botched handoffs are charged to the QB whether the mistake was his fault or not. These plays are also classified as QB rushes even though the QB wasn’t rushing. Let’s take a look at a couple examples of why this matters…

On Sunday the Falcons’ offense botched three snaps. We can debate how much responsibility Matt Ryan bears for those miscues but they were most certainly not all his fault. As is the case with most aborted snaps, none of Atlanta’s led to turnovers and the loss of yardage was minimal. These plays are often no worse than running into a wall for a two yard loss.

If you look at the box score it lists Matt Ryan with three fumbles. Someone who didn’t know the context would think Ryan spent the game waving the ball around like he was trying to hail a taxi. But these weren’t real fumbles, at least not in the way that football fans generally think of them.

In Monday night’s game the Bills fumbled a handoff between Josh Allen and Matt Breida. It was probably 80% Breida’s fault but of course Allen gets charged with a lost fumble. Given the way Allen plays, a box score observer would naturally assume that he must have coughed up the ball on one of his crazy scramble attempts. But that wasn’t the case at all.

Back to the actual point of this rant, let’s dissect how these fumble rulings affect QBR scores (they don’t affect PFF as far as I know). We know that QBR places extreme weight on QB runs and we know that aborted snaps are treated as QB runs. This becomes a confluence of stupidity that defies any semblance of logic. According to QBR, Matt Ryan wasn’t just the worst rushing QB this week, he was more than twice as bad as the second worst. That’s entirely a product of the aborted snaps and the way they’re credited.

The situation with Josh Allen is even more ridiculous. He had a 21 yard scramble in a high leverage situation in addition to a couple of other successful runs. Normally the stuff QBR absolutely drools over. Instead, Allen is credited with negative rush EPA despite his obviously positive performance. Why? You guessed it, because he got charged with a massive EPA loss for Breida’s fumble. According to PFF Allen had the second highest rushing grade of any QB this week. Yet QBR has him third from the bottom.

Both Ryan and Allen were dealt QBR scores in the 20’s despite average overall performances. That’s what happens when you take a few plays with wonky accounting and compound the error by putting extreme weight on the subset of plays that happen to include the wonky ones. I don’t think it’s an exaggeration to infer that Ryan and Allen would’ve had QBR’s around 50 if we simply removed the questionably assigned fumbles.

One of my offseason projects will be an attempt to reverse engineer the rushing component of QBR and make it more reasonable. It’s a shame because the other components (passing, sacks, penalties) are expertly calibrated and tell a very accurate picture of how well the quarterback performed. If the rushing component were fixed, QBR would be a genuinely fantastic metric.

In the meantime I’ve decided to tweak the weights in my ranking formula to minimize some of the noise from QBR’s rushing roulette. From now on PFF grades will be weighted 1.25 units and QBR will be downgraded to 0.75 units.

With that off my chest, here are the season rankings:

#	QB 2021 Season	Plays	PFF	QBR	zPlays	zPFF	zQBR	zAvg	Diff
1	Tom Brady	563	92.1	66.2	1.17	1.81	1.45	1.58	0.36
2	Justin Herbert	576	86.0	67.3	1.31	1.19	1.55	1.32	0.36
3	Kirk Cousins	513	89.6	56.5	0.64	1.56	0.62	1.09	0.93
4	Josh Allen	564	82.2	57.3	1.18	0.80	0.69	0.84	0.11
5	Aaron Rodgers	432	82.7	65.2	-0.23	0.85	1.37	0.79	0.52
6	Matthew Stafford	498	78.4	65.9	0.47	0.41	1.43	0.73	1.02
7	Kyler Murray	365	82.7	65.6	-0.96	0.85	1.40	0.65	0.55
8	Joe Burrow	461	87.1	48.7	0.08	1.30	-0.04	0.65	1.34
9	Derek Carr	541	80.4	55.0	0.94	0.61	0.49	0.64	0.12
10	Dak Prescott	505	83.7	49.7	0.55	0.95	0.04	0.60	0.91
11	Ryan Tannehill	494	81.4	53.8	0.43	0.72	0.39	0.56	0.32
12	Mac Jones	466	83.0	51.4	0.13	0.88	0.19	0.52	0.69
13	Patrick Mahomes	579	73.2	56.5	1.35	-0.13	0.62	0.39	0.75
14	Jalen Hurts	514	80.0	48.0	0.65	0.57	-0.10	0.38	0.68
15	Carson Wentz	518	73.0	58.5	0.69	-0.15	0.79	0.30	0.94
16	Tua Tagovailoa	329	78.8	58.2	-1.34	0.45	0.77	0.19	0.32
17	Matt Ryan	501	76.5	48.0	0.51	0.21	-0.10	0.18	0.32
18	Lamar Jackson	567	70.1	50.3	1.22	-0.44	0.09	0.05	0.54
19	Jimmy Garoppolo	373	73.7	56.3	-0.87	-0.07	0.61	-0.03	0.68
20	Teddy Bridgewater	463	74.3	47.4	0.10	-0.01	-0.16	-0.03	0.14
21	Jacoby Brissett	278	76.0	50.4	-1.89	0.16	0.10	-0.27	0.06
22	Daniel Jones	472	71.6	41.0	0.20	-0.29	-0.70	-0.32	0.41
23	Taylor Heinicke	492	65.9	50.1	0.41	-0.87	0.08	-0.33	0.95
24	Russell Wilson	328	73.9	44.5	-1.35	-0.05	-0.40	-0.42	0.35
25	Ben Roethlisberger	479	58.8	44.3	0.27	-1.60	-0.42	-0.87	1.18
26	Baker Mayfield	389	65.3	37.9	-0.70	-0.94	-0.97	-0.90	0.03
27	Trevor Lawrence	541	59.4	33.7	0.94	-1.54	-1.33	-0.98	0.22
28	Sam Darnold	381	62.6	35.2	-0.78	-1.21	-1.20	-1.12	0.02
29	Jared Goff	481	60.3	30.8	0.29	-1.45	-1.57	-1.14	0.12
30	Justin Fields	299	64.2	25.8	-1.67	-1.05	-2.00	-1.46	0.95
31	Zach Wilson	291	58.5	25.0	-1.75	-1.63	-2.07	-1.79	0.43
32	Davis Mills	270	56.2	30.4	-1.98	-1.87	-1.61	-1.81	0.26

What are your thoughts?