Tony Romo and High Variance QBs

It's too bad we won't get to watch Tony Romo play for the N.F.C. East championship Sunday Night due to injury, because he always seems to add drama to a game. Just look at his last two starts. In week 15 he helped blow a 23-point halftime lead with a -0.13 Win Probability Added (WPA) performance, but in week 16 he threw the game-winning TD pass in the final seconds and put up a +0.64 WPA performance to keep his team's playoff alive.

Romo has a reputation as a choker, mostly due to his team's late-season under-performance. But taken as a whole, his numbers are very "clutch." He has ranked 8th, 5th, 6th, 3rd and 12th in QB WPA over his last 5 (non-injury seasons). I don't buy the choker label, but I do buy the notion that he's a gambler and an improviser, which can cause wide swings in his game-to-game WPA numbers. So I thought I'd pull the stats and investigate how Romo compares in terms of his game-wise variance.

Variance measures how wildly a stat changes. In this analysis, I measured the variance of week-to-week WPA. If a player has lots of heroic games and lots of calamitous games, his WPA variance will be high. If a player is relatively consistent from week-to-week, regardless if he is consistently good or consistently bad, his WPA variance will be low.

For those who are unfamiliar, variance is an average of the squared deviation from each player's mean WPA. For statistical sticklers out there, I used variance of a population rather than variance of a sample--otherwise players with relatively few starts would have a slightly inflated result.

This season, Romo ranks only 14th in game-to-game WPA variance out of the 41 QBs with 200 or more qualifying plays. He's also 14th over the past 5 seasons. If we go back to 1999, the earliest year of my data, he ranks 9th out of the 101 QBs with 800 or more qualifying plays. His early career was apparently very boom-and-bust.

Here are a three tables of QB WPA variance. The first is for the 2013 season through week 16. The second is for the last five seasons. And the third for the period 1999-2013.




2013 Quarterback WPA Variance (min 200 plays)

Rank	Quarterback	WPA Var.	Play Count
1	10-M.Flynn	0.196	214
2	17-P.Rivers	0.180	609
3	4-R.Fitzpatrick	0.156	408
4	7-M.Vick	0.152	203
5	16-M.Cassel	0.144	254
6	10-J.Locker	0.144	233
7	7-G.Smith	0.133	548
8	17-J.Campbell	0.130	313
9	7-C.Kaepernick	0.128	543
10	10-R.Griffin	0.128	610
11	9-M.Stafford	0.127	689
12	17-R.Tannehill	0.125	663
13	1-C.Newton	0.120	615
14	9-T.Romo	0.118	628
15	18-P.Manning	0.117	724
16	2-M.Ryan	0.115	702
17	5-J.Flacco	0.112	677
18	14-A.Dalton	0.105	663
19	12-J.McCown	0.102	265
20	7-C.Keenum	0.095	294
21	9-N.Foles	0.093	393
22	2-T.Pryor	0.085	361
23	6-J.Cutler	0.082	395
24	3-E.Manuel	0.082	418
25	3-C.Palmer	0.079	632
26	12-T.Brady	0.071	713
27	8-M.Glennon	0.070	476
28	11-A.Smith	0.068	665
29	12-A.Luck	0.066	671
30	7-B.Roethlisberger	0.065	644
31	9-D.Brees	0.056	738
32	8-M.Schaub	0.053	364
33	12-A.Rodgers	0.051	317
34	8-S.Bradford	0.043	306
35	3-R.Wilson	0.036	557
36	7-C.Ponder	0.036	311
37	10-K.Clemens	0.030	270
38	10-E.Manning	0.030	621
39	7-C.Henne	0.025	546
40	3-B.Weeden	0.021	326
41	14-M.McGloin	0.020	243

2009-2013 Quarterback WPA Variance (min 400 plays)

Rank	Quarterback	WPA Var.	Play Count
1	9-M.Stafford	0.160	2871
2	4-R.Fitzpatrick	0.156	408
3	9-D.Garrard	0.153	1150
4	6-M.Sanchez	0.143	2433
5	7-G.Smith	0.133	548
6	9-N.Foles	0.133	712
7	3-R.Wilson	0.132	1166
8	13-K.Warner	0.126	654
9	10-M.Flynn	0.123	404
10	5-J.Flacco	0.122	3556
11	6-J.Cutler	0.121	2580
12	4-B.Favre	0.121	1129
13	17-P.Rivers	0.119	3193
14	9-T.Romo	0.118	3019
15	10-R.Griffin	0.112	1213
16	7-B.Roethlisberger	0.103	3076
17	9-D.Brees	0.103	3836
18	8-K.Orton	0.101	1513
19	2-M.Ryan	0.099	3483
20	10-J.Locker	0.096	720
21	10-E.Manning	0.093	3345
22	8-S.Bradford	0.093	2047
23	14-A.Dalton	0.091	1989
24	4-K.Kolb	0.090	904
25	3-B.Weeden	0.088	920
26	17-R.Tannehill	0.088	1270
27	12-A.Luck	0.088	1517
28	14-Sh.Hill	0.085	492
29	8-M.Schaub	0.085	2756
30	3-E.Manuel	0.082	418
31	1-C.Newton	0.081	2022
32	8-R.Grossman	0.081	661
33	8-J.Campbell	0.079	650
34	7-M.Cassel	0.079	1881
35	7-C.Kaepernick	0.079	982
36	9-C.Palmer	0.077	1276
37	15-T.Tebow	0.077	701
38	5-D.McNabb	0.077	1358
39	18-P.Manning	0.076	2979
40	17-J.Campbell	0.075	936
41	14-R.Fitzpatrick	0.075	2108
42	7-C.Henne	0.075	2165
43	11-A.Smith	0.073	2471
44	5-J.Freeman	0.073	2307
45	8-M.Moore	0.072	437
46	7-M.Vick	0.070	1839
47	12-A.Rodgers	0.070	3331
48	8-M.Glennon	0.070	476
49	11-B.Gabbert	0.062	988
50	19-J.Skelton	0.058	722
51	12-C.McCoy	0.057	905
52	12-T.Brady	0.057	3735
53	7-C.Ponder	0.056	1281
54	3-C.Palmer	0.055	1663
55	3-D.Anderson	0.055	602
56	10-V.Young	0.055	541
57	17-J.Delhomme	0.055	586
58	8-M.Hasselbeck	0.051	2034
59	5-K.Collins	0.040	673
60	3-J.Kitna	0.039	403
61	7-T.Jackson	0.026	657

1999-2013 Quarterback WPA Variance (min 800 plays)

Rank	Quarterback	WPA Var.	Play Count
1	7-S.Beuerlein	0.179	1282
2	11-D.Bledsoe	0.165	4139
3	9-M.Stafford	0.160	2871
4	6-M.Sanchez	0.143	2433
5	3-R.Wilson	0.132	1166
6	13-K.Warner	0.127	5233
7	2-T.Couch	0.125	2145
8	4-B.Favre	0.123	7817
9	9-T.Romo	0.121	4727
10	6-J.Cutler	0.121	4050
11	18-E.Grbac	0.120	1824
12	9-D.Garrard	0.120	3063
13	12-T.Banks	0.120	1380
14	5-J.Flacco	0.114	4198
15	2-A.Brooks	0.112	3849
16	10-R.Griffin	0.112	1213
17	8-J.Kitna	0.112	1554
18	11-D.Culpepper	0.110	3984
19	12-R.Gannon	0.108	3279
20	3-D.Anderson	0.108	1687
21	3-J.George	0.107	800
22	17-P.Rivers	0.105	5106
23	10-T.Green	0.105	3846
24	10-M.Bulger	0.102	3875
25	7-J.Kitna	0.101	1166
26	9-D.Brees	0.101	8225
27	9-C.Palmer	0.101	3807
28	8-K.Orton	0.101	1513
29	9-S.McNair	0.101	4606
30	9-J.Fiedler	0.100	2148
31	14-B.Griese	0.100	2603
32	10-E.Manning	0.099	6284
33	7-B.Roethlisberger	0.097	5830
34	8-T.Maddox	0.096	1486
35	5-D.McNabb	0.094	7469
36	16-J.Plummer	0.094	4537
37	2-M.Ryan	0.094	4065
38	8-S.Bradford	0.093	2047
39	16-M.Cassel	0.092	982
40	8-M.Schaub	0.091	3811
41	14-A.Dalton	0.091	1989
42	10-K.Holcomb	0.090	939
43	14-B.Johnson	0.090	4293
44	3-J.Kitna	0.090	2447
45	5-K.Collins	0.090	5778
46	8-M.Brunell	0.089	3677
47	3-B.Weeden	0.088	920
48	17-R.Tannehill	0.088	1270
49	12-A.Luck	0.088	1517
50	15-J.Miller	0.086	1118
51	7-M.Vick	0.086	4583
52	18-K.Orton	0.086	1099
53	17-J.Delhomme	0.085	3641
54	5-J.Garcia	0.085	3606
55	10-C.Pennington	0.084	3208
56	8-T.Aikman	0.084	867
57	7-J.Losman	0.083	1205
58	7-J.Garcia	0.082	1203
59	10-S.King	0.082	974
60	18-P.Manning	0.082	9795
61	1-C.Newton	0.081	2022
62	12-G.Frerotte	0.081	1588
63	7-K.Boller	0.079	1418
64	17-J.Campbell	0.079	2302
65	7-M.Cassel	0.079	1881
66	7-C.Kaepernick	0.079	982
67	12-J.McCown	0.078	1644
68	16-V.Testaverde	0.078	2497
69	7-D.Flutie	0.077	1817
70	7-B.Leftwich	0.077	1818
71	12-T.Brady	0.077	8786
72	11-R.Johnson	0.076	939
73	17-Q.Carter	0.076	1281
74	14-R.Fitzpatrick	0.075	2108
75	11-A.Smith	0.075	3501
76	7-C.Henne	0.074	2178
77	5-J.Freeman	0.073	2307
78	4-K.Kolb	0.072	959
79	8-R.Grossman	0.070	1936
80	12-A.Rodgers	0.070	4074
81	8-M.Hasselbeck	0.069	6525
82	8-B.Griese	0.069	850
83	11-D.Huard	0.069	1201
84	2-A.Wright	0.068	830
85	3-J.Harrington	0.067	2525
86	10-V.Young	0.065	1638
87	11-J.Blake	0.064	888
88	5-T.Edwards	0.064	1124
89	11-B.Gabbert	0.062	988
90	8-D.Carr	0.061	3004
91	10-K.Stewart	0.058	2094
92	12-C.McCoy	0.057	905
93	7-T.Jackson	0.057	1386
94	10-C.Batch	0.057	1285
95	16-C.Weinke	0.057	836
96	11-P.Ramsey	0.056	1112
97	7-C.Ponder	0.056	1281
98	3-C.Palmer	0.055	1663
99	12-C.Chandler	0.054	1739
100	13-T.Rattay	0.054	830
101	2-J.Russell	0.051	840