Quick note: Yards per play by down

Like most of my posts, this one does not have a grand overall theme. Instead, I was driving home from work and wondered if yards per play varied by down (and distance and placement on the field and quarter and score and month, but I'll get to those later). And yards per play does vary by down. Nationally, 3rd down is best for offenses, 1st is second best and 2nd after that. I have not included data on 4th downs because there are serious issues with sample size for some teams, but on average 4th down is far below the other three (teams usually only go for it on 4th down when they are close, and they run a play to maximize their probability of getting that 1st down). 

I've listed team averages, each team's performance relative to the rest of the league and relative to their expected performance (green is good, red is bad). The expected is calculated using the team's yards per play on all plays, the league's yards per play on all plays and on that down. So, for example, Baylor is good on 2nd down versus the league average (1st column is green), but not good versus expected (2nd column is yellow) because Baylor had a better than league average offense. Baylor is quite bad on 3rd down versus expected because they are better on 2nd and 1st downs.

In general, passing teams are better on 3rd down and running teams better on 1st down (the correlation is non-negligible but not overwhelming). Every team passed the ball more on 3rd down than on the first two downs, and the typical team ran the ball 33% fewer times on 3rd down, thus giving the advantage to teams that generally preferred to throw the ball more. 

Surprisingly, there was a stronger correlation between teams having a good offense generally and teams being bad on 3rd down. Baylor, as already mentioned, Georgia Tech, Houston, Oklahoma, Oklahoma St. (to a lesser degree), Oregon, USC, Stanford, and Washington were all near the top of the league in yards per play and near the bottom in yards per play on 3rd down versus expected (the Pac-10 was also apparently quite bad on 3rd downs). 

Alabama was almost 2 yards worse on 2nd down than on 1st and 3rd. 

Yards per play by down Colored columns: 1) vs. League Average; 2) vs. Expected
	1st down				2nd down				3rd down
FBS Average	5.90				5.75				6.05
Air Force	6.94	1.04		0.58	5.87	0.12		-0.34	5.31	-0.74		-1.20
Akron	4.83	-1.07		0.19	4.54	-1.22		0.04	4.13	-1.93		-0.66
Alabama	7.32	1.42		0.60	5.45	-0.30		-1.12	7.22	1.17		0.35
Arizona	5.93	0.03		-0.49	7.42	1.67		1.15	6.03	-0.02		-0.54
Arizona St.	6.54	0.64		0.07	5.96	0.21		-0.36	7.04	0.99		0.42
Arkansas	7.01	1.11		0.10	6.12	0.37		-0.65	7.78	1.73		0.72
Arkansas St.	6.05	0.15		0.10	5.75	0.00		-0.06	6.07	0.02		-0.03
Army	5.78	-0.12		0.01	6.07	0.31		0.45	5.57	-0.48		-0.34
Auburn	5.36	-0.54		-0.42	5.72	-0.03		0.09	6.61	0.56		0.68
BYU	5.43	-0.47		-0.27	5.87	0.12		0.32	5.99	-0.06		0.14
Ball St.	5.02	-0.88		-0.46	5.52	-0.23		0.19	5.51	-0.54		-0.12
Baylor	8.39	2.49		0.47	7.83	2.08		0.06	6.27	0.22		-1.80
Boise St.	6.27	0.37		-0.29	6.73	0.98		0.32	6.63	0.58		-0.09
Boston College	4.92	-0.98		-0.11	4.72	-1.04		-0.17	5.87	-0.18		0.69
Bowling Green	6.22	0.32		0.39	5.38	-0.37		-0.30	5.59	-0.46		-0.39
Buffalo	5.36	-0.54		0.02	5.64	-0.11		0.45	4.71	-1.34		-0.78
California	5.79	-0.11		-0.31	5.35	-0.40		-0.60	7.72	1.67		1.47
Central Mich.	6.93	1.03		0.58	5.19	-0.56		-1.01	6.83	0.78		0.34
Cincinnati	5.38	-0.52		-0.52	6.16	0.41		0.40	6.55	0.50		0.50
Clemson	6.05	0.15		-0.19	6.25	0.50		0.16	6.29	0.24		-0.09
Colorado	5.19	-0.71		-0.60	5.99	0.24		0.34	6.32	0.27		0.37
Colorado St.	5.46	-0.44		-0.32	6.58	0.83		0.96	5.39	-0.66		-0.54
Connecticut	5.28	-0.62		0.19	5.07	-0.68		0.13	4.50	-1.55		-0.74
Duke	5.05	-0.85		-0.39	5.13	-0.62		-0.16	6.50	0.45		0.91
East Carolina	4.96	-0.94		-0.65	6.10	0.35		0.64	5.86	-0.19		0.10
Eastern Mich.	5.76	-0.14		0.19	5.19	-0.56		-0.23	5.80	-0.25		0.08
FIU	6.06	0.16		0.36	4.50	-1.25		-1.06	6.85	0.80		0.99
Fla. Atlantic	4.57	-1.33		-0.06	4.29	-1.46		-0.19	5.29	-0.76		0.51
Florida	6.05	0.15		0.31	5.34	-0.42		-0.25	5.65	-0.40		-0.24
Florida St.	5.81	-0.09		-0.39	6.23	0.48		0.18	7.18	1.13		0.83
Fresno St.	7.06	1.16		0.75	6.11	0.36		-0.05	5.10	-0.96		-1.36
Georgia	6.48	0.58		0.42	5.24	-0.51		-0.66	6.14	0.09		-0.06
Georgia Tech	7.14	1.24		0.32	6.80	1.05		0.13	6.12	0.06		-0.85
Hawaii	6.75	0.85		0.42	5.33	-0.43		-0.85	6.79	0.74		0.31
Houston	8.41	2.51		0.53	7.33	1.58		-0.40	7.56	1.51		-0.47
Idaho	4.61	-1.29		-0.18	4.58	-1.17		-0.06	5.36	-0.69		0.42
Illinois	4.75	-1.15		-0.84	6.21	0.46		0.76	6.05	0.00		0.30
Indiana	5.51	-0.39		0.14	4.99	-0.77		-0.23	5.69	-0.36		0.18
Iowa	5.91	0.01		-0.13	6.24	0.48		0.35	5.88	-0.17		-0.31
Iowa St.	4.63	-1.27		-0.69	5.59	-0.16		0.42	6.20	0.15		0.73
Kansas	4.84	-1.07		-0.20	4.96	-0.80		0.07	5.67	-0.38		0.48
Kansas St.	5.96	0.06		0.46	4.80	-0.95		-0.55	5.45	-0.60		-0.20
Kent St.	4.14	-1.76		-0.20	4.57	-1.18		0.37	4.75	-1.30		0.25
Kentucky	3.14	-2.76		-0.59	4.17	-1.58		0.59	4.17	-1.88		0.29
LSU	6.12	0.22		0.16	5.79	0.04		-0.02	5.55	-0.50		-0.56
La.-Lafayette	5.94	0.04		-0.19	5.60	-0.15		-0.38	6.71	0.66		0.43
La.-Monroe	4.35	-1.55		-0.76	5.42	-0.34		0.45	6.05	0.00		0.79
Louisiana Tech	5.86	-0.04		0.40	4.94	-0.82		-0.38	5.37	-0.68		-0.24
Louisville	4.95	-0.95		-0.72	5.66	-0.10		0.14	6.69	0.64		0.88
Marshall	5.42	-0.48		0.06	4.71	-1.04		-0.50	6.16	0.11		0.65
Maryland	5.89	-0.01		0.27	5.34	-0.41		-0.13	5.95	-0.10		0.17
Memphis	4.92	-0.98		0.49	3.84	-1.91		-0.44	4.41	-1.64		-0.17
Miami (FL)	6.50	0.60		0.05	6.47	0.72		0.16	6.59	0.54		-0.02
Miami (OH)	6.08	0.18		-0.11	6.47	0.72		0.43	6.02	-0.03		-0.32
Michigan	6.47	0.57		-0.12	6.42	0.66		-0.02	7.43	1.38		0.69
Michigan St.	5.55	-0.35		-0.09	5.54	-0.21		0.05	5.84	-0.21		0.05
Middle Tenn.	4.67	-1.23		-0.54	5.73	-0.02		0.67	5.52	-0.53		0.16
Minnesota	4.98	-0.92		-0.24	5.76	0.00		0.69	4.98	-1.07		-0.38
Mississippi	4.70	-1.20		-0.24	5.10	-0.65		0.30	5.25	-0.80		0.15
Mississippi St.	5.62	-0.28		0.06	5.62	-0.14		0.20	5.41	-0.64		-0.31
Missouri	6.51	0.61		0.39	5.86	0.11		-0.11	5.54	-0.51		-0.73
Navy	6.51	0.61		0.56	5.08	-0.67		-0.71	6.34	0.29		0.24
Nebraska	6.20	0.30		0.52	5.32	-0.43		-0.22	5.27	-0.78		-0.56
Nevada	6.74	0.84		0.10	6.27	0.52		-0.22	7.06	1.01		0.27
New Mexico	5.20	-0.70		0.13	4.76	-0.99		-0.16	5.61	-0.44		0.39
New Mexico St.	6.28	0.38		0.01	5.85	0.10		-0.27	6.85	0.80		0.42
North Carolina	7.10	1.20		0.36	5.57	-0.18		-1.01	7.84	1.78		0.95
North Carolina St.	4.81	-1.09		-0.47	4.77	-0.99		-0.37	6.74	0.69		1.31
North Texas	5.47	-0.43		0.23	4.69	-1.06		-0.40	5.92	-0.13		0.53
Northern Ill.	7.18	1.28		0.69	5.96	0.21		-0.38	5.75	-0.30		-0.88
Northwestern	5.46	-0.44		-0.70	6.19	0.44		0.18	7.78	1.73		1.48
Notre Dame	6.58	0.68		0.36	5.94	0.19		-0.12	5.64	-0.41		-0.72
Ohio	6.87	0.97		0.39	6.03	0.28		-0.30	6.17	0.12		-0.46
Ohio St.	5.73	-0.17		-0.03	5.57	-0.18		-0.03	6.11	0.06		0.20
Oklahoma	7.03	1.13		0.49	6.16	0.40		-0.23	5.88	-0.17		-0.81
Oklahoma St.	7.67	1.77		0.29	7.01	1.26		-0.22	7.12	1.07		-0.41
Oregon	7.15	1.25		-0.14	7.68	1.93		0.54	6.54	0.48		-0.90
Oregon St.	5.28	-0.62		-0.63	6.28	0.53		0.52	6.62	0.57		0.57
Penn St.	5.04	-0.86		-0.17	5.34	-0.41		0.27	5.45	-0.60		0.09
Pittsburgh	5.59	-0.31		-0.11	6.11	0.36		0.57	5.25	-0.80		-0.60
Purdue	5.38	-0.52		-0.12	5.72	-0.03		0.37	5.27	-0.78		-0.39
Rice	5.54	-0.36		0.23	4.65	-1.10		-0.51	5.90	-0.15		0.44
Rutgers	5.13	-0.77		-0.03	4.73	-1.02		-0.29	5.58	-0.47		0.27
SMU	6.37	0.47		-0.17	6.29	0.53		-0.11	7.26	1.21		0.57
San Diego St.	6.59	0.69		0.49	5.28	-0.48		-0.67	6.49	0.43		0.24
San Jose St.	5.28	-0.62		-0.37	5.28	-0.47		-0.22	7.07	1.02		1.27
South Carolina	5.99	0.09		0.05	5.44	-0.31		-0.35	6.07	0.02		-0.01
South Fla.	6.57	0.67		0.71	5.94	0.19		0.23	3.84	-2.21		-2.17
Southern California	6.71	0.81		-0.10	7.18	1.43		0.52	6.17	0.12		-0.79
Southern Miss.	6.16	0.26		-0.26	6.54	0.79		0.26	6.62	0.56		0.04
Stanford	7.06	1.16		0.08	7.30	1.55		0.47	6.20	0.15		-0.93
Syracuse	5.68	-0.22		0.13	5.04	-0.71		-0.36	5.76	-0.29		0.07
TCU	6.12	0.22		-0.51	6.58	0.83		0.09	7.84	1.79		1.05
Temple	6.53	0.63		0.22	5.37	-0.38		-0.78	6.93	0.88		0.48
Tennessee	5.33	-0.57		0.02	4.75	-1.00		-0.41	6.15	0.10		0.69
Texas	5.77	-0.13		-0.09	5.08	-0.67		-0.63	7.38	1.33		1.37
Texas A&M	5.40	-0.50		-0.80	7.03	1.28		0.97	6.78	0.73		0.42
Texas St.	5.76	-0.14		0.35	5.78	0.03		0.52	4.45	-1.60		-1.11
Texas Tech	5.95	0.05		0.00	6.34	0.58		0.54	5.39	-0.66		-0.71
Toledo	6.23	0.33		-0.26	6.60	0.85		0.26	6.96	0.91		0.31
Troy	5.89	-0.01		0.29	5.39	-0.36		-0.07	5.47	-0.58		-0.29
Tulane	5.53	-0.37		0.29	5.05	-0.71		-0.04	5.02	-1.03		-0.36
Tulsa	6.48	0.58		0.14	6.29	0.53		0.10	6.10	0.05		-0.38
UAB	4.96	-0.94		-0.51	6.27	0.52		0.95	5.41	-0.65		-0.21
UCF	7.25	1.35		0.93	5.37	-0.38		-0.80	5.82	-0.23		-0.64
UCLA	6.54	0.64		0.28	6.56	0.81		0.45	5.20	-0.85		-1.21
UNLV	5.45	-0.45		0.71	4.57	-1.19		-0.02	3.58	-2.48		-1.31
UTEP	5.33	-0.57		-0.89	7.08	1.33		1.00	6.36	0.31		-0.02
UTSA	6.26	0.35		0.44	5.01	-0.74		-0.66	5.89	-0.16		-0.08
Utah	5.90	0.00		0.33	5.04	-0.72		-0.39	5.21	-0.84		-0.51
Utah St.	6.84	0.94		0.22	6.29	0.54		-0.19	6.80	0.75		0.03
Vanderbilt	4.84	-1.06		-0.86	6.25	0.49		0.69	6.01	-0.04		0.16
Virginia	5.71	-0.19		-0.02	5.71	-0.05		0.13	5.77	-0.28		-0.10
Virginia Tech	5.97	0.07		-0.05	5.96	0.21		0.08	6.34	0.28		0.16
Wake Forest	5.85	-0.06		0.12	5.66	-0.09		0.08	5.46	-0.59		-0.41
Washington	6.92	1.02		0.12	6.79	1.04		0.14	6.39	0.34		-0.56
Washington St.	6.69	0.79		0.46	5.77	0.02		-0.31	6.36	0.31		-0.02
West Virginia	6.85	0.95		0.11	6.59	0.84		0.00	6.72	0.67		-0.17
Western Ky.	4.80	-1.10		-0.46	5.27	-0.49		0.16	6.20	0.14		0.79
Western Mich.	6.92	1.02		0.13	7.08	1.32		0.43	6.30	0.25		-0.65
Wisconsin	7.05	1.15		-0.26	7.44	1.69		0.28	7.49	1.44		0.04
Wyoming	4.83	-1.07		-0.78	5.72	-0.04		0.25	6.81	0.76		1.04