Final 2011 Offensive and Defensive Efficiency Scores

With the 2011 regular season in the books, here are the final efficiency scores:

Offense:

2011	All Time	Tm	OSCORE
1	2	Green Bay Packers	53.95
2	10	New Orleans Saints	48.95
3	17	New England Patriots	42.35
4	144	Carolina Panthers	20.45
5	182	San Diego Chargers	17.65
6	198	Detroit Lions	16.40
7	202	Atlanta Falcons	16.25
8	243	San Francisco 49ers	13.90
9	280	New York Giants	12.60
10	348	Dallas Cowboys	9.85
11	365	Houston Texans	9.10
12	490	Minnesota Vikings	3.60
13	503	Baltimore Ravens	3.20
14	626	Philadelphia Eagles	-1.70
15	675	Oakland Raiders	-3.10
15	675	Miami Dolphins	-3.10
17	681	Pittsburgh Steelers	-3.25
18	723	New York Jets	-4.50
19	733	Cincinnati Bengals	-4.85
20	739	Tennessee Titans	-5.25
21	771	Buffalo Bills	-6.10
22	865	Seattle Seahawks	-10.10
23	919	Arizona Cardinals	-12.95
24	993	Chicago Bears	-16.65
25	1012	Denver Broncos	-17.25
26	1035	Washington Redskins	-18.60
27	1096	Cleveland Browns	-22.80
28	1108	Jacksonville Jaguars	-23.50
29	1135	Tampa Bay Buccaneers	-26.40
30	1149	Indianapolis Colts	-27.80
31	1201	Kansas City Chiefs	-37.95
32	1209	St. Louis Rams	-40.70

Defense:

2011	All Time	Tm	DSCORE
1	20	San Francisco 49ers	36.65
2	84	Baltimore Ravens	25.11
3	135	Seattle Seahawks	20.17
4	195	Houston Texans	16.48
5	211	Chicago Bears	15.81
6	270	New York Jets	12.88
7	300	Detroit Lions	11.78
8	314	Pittsburgh Steelers	11.42
9	324	Green Bay Packers	10.70
10	404	Jacksonville Jaguars	7.44
11	446	New England Patriots	5.93
12	465	Atlanta Falcons	5.42
13	514	Tennessee Titans	4.11
14	565	Cincinnati Bengals	2.28
15	575	Miami Dolphins	1.94
16	578	Cleveland Browns	1.88
17	620	Philadelphia Eagles	0.56
18	621	Kansas City Chiefs	0.54
19	637	Dallas Cowboys	0.13
20	644	Arizona Cardinals	-0.08
21	771	New York Giants	-4.42
22	781	Denver Broncos	-4.86
23	915	Washington Redskins	-11.14
24	921	Buffalo Bills	-11.45
25	943	New Orleans Saints	-12.46
26	955	St. Louis Rams	-13.10
27	982	San Diego Chargers	-14.61
28	1019	Oakland Raiders	-16.24
29	1089	Minnesota Vikings	-21.47
30	1110	Indianapolis Colts	-24.07
31	1137	Carolina Panthers	-26.99
32	1190	Tampa Bay Buccaneers	-34.40

Offensive Efficiency Rankings Through Week 16

Offensive Efficiency Rankings Through Week 16

2011	All Time	Tm	OSCORE
1	2	Green Bay Packers	54.25
2	14	New Orleans Saints	45.45
3	21	New England Patriots	40.55
4	123	Carolina Panthers	22.25
5	202	Detroit Lions	16.05
6	233	San Diego Chargers	14.35
7	263	Atlanta Falcons	13.30
8	282	Dallas Cowboys	12.35
9	320	San Francisco 49ers	10.95
10	336	Houston Texans	10.20
11	352	New York Giants	9.75
12	386	Minnesota Vikings	7.95
13	548	Baltimore Ravens	1.40
14	603	Pittsburgh Steelers	-0.55
15	646	Miami Dolphins	-2.15
16	678	New York Jets	-3.15
17	701	Cincinnati Bengals	-3.95
18	724	Oakland Raiders	-4.60
19	733	Philadelphia Eagles	-4.90
20	736	Buffalo Bills	-5.10
21	758	Tennessee Titans	-5.85
22	863	Seattle Seahawks	-10.05
23	919	Denver Broncos	-12.95
23	919	Arizona Cardinals	-12.95
25	943	Chicago Bears	-13.95
26	1012	Washington Redskins	-17.20
27	1075	Cleveland Browns	-20.85
28	1125	Jacksonville Jaguars	-25.50
29	1129	Tampa Bay Buccaneers	-25.70
30	1137	Indianapolis Colts	-26.60
31	1199	Kansas City Chiefs	-36.40
32	1217	St. Louis Rams	-47.05

2011 Efficiency Rankings Through Week 15

With 15 weeks of the NFL season in the books, here are the OSCORE and DSCORE rankings:

2011	All Time	Tm	OSCORE
1	3	Green Bay Packers	52.35
2	14	New Orleans Saints	43.20
3	21	New England Patriots	40.05
4	185	San Diego Chargers	17.05
5	215	Detroit Lions	15.05
6	231	Atlanta Falcons	14.50
7	241	Dallas Cowboys	14.05
8	252	Carolina Panthers	13.65
9	301	Houston Texans	11.70
10	339	San Francisco 49ers	10.15
11	371	New York Giants	8.90
12	524	Baltimore Ravens	2.10
13	533	Minnesota Vikings	1.90
14	565	New York Jets	0.90
15	672	Buffalo Bills	-2.90
16	673	Cincinnati Bengals	-2.95
17	687	Oakland Raiders	-3.55
18	688	Philadelphia Eagles	-3.55
19	700	Pittsburgh Steelers	-3.85
20	702	Miami Dolphins	-3.90
21	771	Tennessee Titans	-6.10
22	840	Seattle Seahawks	-9.05
23	858	Chicago Bears	-9.90
24	865	Denver Broncos	-10.05
25	931	Arizona Cardinals	-13.25
26	1056	Washington Redskins	-19.75
27	1076	Cleveland Browns	-21.05
28	1110	Tampa Bay Buccaneers	-23.65
29	1129	Jacksonville Jaguars	-25.70
30	1138	Indianapolis Colts	-27.00
31	1192	Kansas City Chiefs	-35.25
32	1213	St. Louis Rams	-43.55

2011	All Time	Tm	DSCORE
1	8	San Francisco 49ers	44.34
2	106	Baltimore Ravens	22.88
3	145	Seattle Seahawks	19.38
4	151	Chicago Bears	18.92
5	157	Houston Texans	18.32
6	252	New York Jets	14.02
7	275	Detroit Lions	12.80
8	318	Green Bay Packers	11.18
9	403	Atlanta Falcons	7.46
10	427	Dallas Cowboys	6.64
11	431	Pittsburgh Steelers	6.44
12	446	New England Patriots	5.98
13	453	Tennessee Titans	5.74
14	530	Miami Dolphins	3.56
15	552	Jacksonville Jaguars	2.94
16	589	Cincinnati Bengals	1.56
17	662	Cleveland Browns	-0.76
18	673	Arizona Cardinals	-1.18
19	735	Philadelphia Eagles	-3.18
20	752	Washington Redskins	-3.54
21	814	Denver Broncos	-6.48
22	843	San Diego Chargers	-7.76
23	852	Kansas City Chiefs	-8.18
24	864	St. Louis Rams	-8.52
25	886	New York Giants	-9.74
26	948	Buffalo Bills	-12.66
27	1005	New Orleans Saints	-15.72
28	1024	Oakland Raiders	-16.54
29	1115	Tampa Bay Buccaneers	-25.00
30	1127	Carolina Panthers	-25.98
31	1143	Indianapolis Colts	-27.38
32	1152	Minnesota Vikings	-28.44

2011 Offensive Efficiency Scores

Yesterday, I posted my final Offensice Efficiency (O-SCORE) rankings for 1970-2010 (you can find them here: 1970-2010 Rankings). Here are the 2011 scores, along with their all-time rank:

2011	All Time	Tm	OSCORE
1	3	Green Bay Packers	52.46
2	18	New Orleans Saints	39.56
3	38	New England Patriots	33.02
4	121	Houston Texans	21.73
5	251	Detroit Lions	13.20
6	292	Atlanta Falcons	11.63
7	302	Dallas Cowboys	11.13
8	354	San Francisco 49ers	9.07
9	385	New York Giants	7.69
10	448	Carolina Panthers	5.05
11	451	Minnesota Vikings	4.95
12	457	Pittsburgh Steelers	4.82
13	460	Buffalo Bills	4.78
14	473	Chicago Bears	4.19
15	513	Oakland Raiders	2.80
16	552	Cincinnati Bengals	1.53
17	567	Baltimore Ravens	0.81
18	582	San Diego Chargers	0.52
19	621	Philadelphia Eagles	-1.00
20	665	Miami Dolphins	-2.63
21	731	Tennessee Titans	-4.71
22	814	New York Jets	-7.70
23	894	Denver Broncos	-10.67
24	913	Cleveland Browns	-11.83
25	996	Arizona Cardinals	-15.90
26	1042	Tampa Bay Buccaneers	-17.60
27	1053	Seattle Seahawks	-18.21
28	1105	Washington Redskins	-22.08
29	1145	Jacksonville Jaguars	-26.49
30	1182	Indianapolis Colts	-31.45
31	1193	Kansas City Chiefs	-33.77
32	1209	St. Louis Rams	-37.79

Through 11 weeks, the Packers have the 3rd most efficient offense since the 1970 NFL/AFL merger. They still trail the 2007 Patriots significantly in most variables, so I doubt they will get to #1. It’s possible that they overtake the 1984 Dolphins (52.64) though, given Green Bay’s fairly soft schedule the last 5 weeks.

On the other end of the spectrum, the 2011 Rams have the 13th worst offense since 1970. It’s possible (especially if A.J. Feeley gets more starts) that they drop into the bottom 10 but even a total collapse probably wouldn’t get them in the bottom 3.  St. Louis’ 2009 offense was 5th worst since 1970. The Tampa Bay Buccaneers (1976, 1977) are the only other team to have two appearances in the bottom 20 within 5 years of each other. The 1977 and 1985 Buffalo Bills and 1972 and 1998 Eagles are the other repeat offenders.

The big surprise for me here is the Minnesota Vikings being a little better than the Steelers. This is mostly due to turnover % (the Steelers  have had 5% more offensive drives end in a turnover than Minnesota) and Yards Per Point (the Steelers are 23rd best, the Vikings are 16th).

O-Score: Final Rankings

In case you missed it, here are the first five parts to this series:

O-Score: Measuring Offensive Efficiency (A Preface)

Offensive Efficiency: Yards Per Drive

Offensive Efficiency: Turnovers

Offensive Efficiency: TD% And Points Per Drive

Offensive Efficiency: Yards Per Point

Some final thoughts on our variables before we look at the final scores:

– Turnovers: It seems like common sense that a team that turns the ball over a lot is unlikely to score a lot of points – but that’s not necessarily the case. In fact, a team’s turnover rate is only very weakly linked to their points scoring. The 1977 Cleveland Browns, 2001 St. Louis Rams and 1993 Houston Oilers all had offenses which scored 10%+ more than league average but are all bottom 2o (since 1970) teams in turnover ratio. However, of the 50 teams which turned the ball over the least, only 5 had worse-than-average scoring offenses (measured by points per drive). The conclusion here seems to be that great scoring offenses who turn the ball over a lot aren’t hurt too much since they are so efficient at turning their other drives into points. Offenses which turn the ball over a lot tend to be mediocre or worse at scoring points, but some of that is probably due to a lack of talent. After all, how many great QB’s turn the ball over a ton? How many high-quality RB’s fumble a lot? A few, for sure. But in general, elite scoring offenses are laden with elite talent – the type of which doesn’t turn the ball over and can overcome the mistakes they do make. The negatives effects of offensive turnovers are more likely to appear in their team’s defensive stats.

– Yards Per Drive: Again, the takeaway point here is that great scoring offenses generate a lot of yards per drive. Teams who have high points-per-game or points-per-drive tend to have high TD%. Because TD drives are (usually) longer than drives which end in field goals or punts, a high YPD is very common amongst high TD% teams. Since 1970, there have been 571 offenses which have been below-average in terms of YPD. Of those, only a mere 83 (14.5%) put up a PPD better than league average.

-TD% – A variable which is closely tied to Points Per Drive. Touchdown drives maximize the number of points your team scores (i.e. it’s unlikely you will be outscored in a game if you score a TD on every drive, assuming a PAT conversion, your opponent would either need an extra drive or to make a 2 point conversion). Furthermore, drives which end in TD’s obviously cannot end in turnovers or punts – both of which can lead to an opponent scoring a non-offensive TD.

– Yards Per Point – At the risk of sounding redundant, great scoring offenses almost always have high YPP rankings. However, there is a large “middle class” of YPP offenses which under-perform their expected PPD ranking. This could be due to a number of variables (shaky field goal kicker, red zone troubles, turnovers, etc). It’s rare for a below average YPP offense to have an above average PPD (about 15%). This stat can be skewed a little by a team having an elite defense or special teams – creating an unusually high number of short fields for the offense.

-Points Per Drive – This is the most important measure of an offense. It tells us what the offense does with what they are given. It’s a much better way to measure an offense than Points Per Game – as teams with terrible defenses will have fewer offensive opportunities. The problem with using PPD as the sole measure of offensive efficiency is that it doesn’t the whole story. Imagine these two scenarios:

Team A: 8 offensive drives, 8 FG’s = 3 PPD

Team B: 8 offensive drives, 4 TD, 2 punts, 2 turnovers = 3.5 PPD

While team B scored 4 more points (assuming XP and not 2 point conversions), the 2 turnovers and 2 punts are more likely to lead to their opponent scoring than Team A’s 8 kickoffs (even more the case with the new kickoff rules). Therefore, while team B scored more points, they are more likely to give up more points – assuming league average defense and special teams for both Team A and Team B. Another way to think of this is that Team B’s offensive points are worth less than Team A’s

So, in coming with my final scoring system, I took these five variables and weighted them in this order:

Points Per Drive

Yards Per Point

TO%

TD%

Yards Per Drive

All variables were taken as a percentage of league average. For example the 2007 New England Patriots had a YPD of 43.58, which was 40% better than league average. So for my rankings, I assigned them a YPD value of 45. The 2007 San Francisco 49ers had a YPD of 20.98, 33% worse than league average, so they get a value of -33.

The coefficients by which I weighted each variable were determined largely by a series of linear regression models. If you’re unfamiliar with regression analysis, it’s a way of mathematically determining the effect a variety of different variables have on another variable. The goal was to determine which offense gave their team the best overall chance to win, assuming a league average defense. Because the math is as boring as it is complicated for most, I’ll skip it for now (and revisit it perhaps in a future post for the math geeks out there).

The other, smaller, part of the coefficients is much less scientific. There’s a point to which stats unfortunately can’t explain everything. There’s simply no way to know how many times a drive which ends in a turnover would have otherwise ended in a score. Furthermore, there is very limited data (in terms of years) available on things like points of turnovers and red zone scoring %. There’s also stuff which isn’t reflected in stats, such as “can this offense effectively run out the clock when they’re winning, even if they’re not a high-scoring team” (YPD is probably the closest we can come to figuring that out statistically). To this end, I put a little additional weight on TO% and YPD and a little less weight on TD% (which is partially overlapped by PPD anyway).

Here are the top and bottom 20 offenses of all time. For rankings of every team since 1970 click here. Keep in mind that an OSCORE of 0 would be exactly average

Top 20:

Rank	Year	Tm	OSCORE
1	2007	New England Patriots	65.48
2	1984	Miami Dolphins	52.64
3	2010	New England Patriots	50.26
4	2004	Indianapolis Colts	49.62
5	1994	San Francisco 49ers	49.22
6	1993	San Francisco 49ers	49.19
7	1998	Minnesota Vikings	49.04
8	1992	San Francisco 49ers	48.86
9	1982	San Diego Chargers	47.26
10	1976	Baltimore Colts	45.80
11	2000	St. Louis Rams	45.25
12	2006	San Diego Chargers	43.11
13	2005	Indianapolis Colts	41.36
14	2006	Indianapolis Colts	41.29
15	1998	Denver Broncos	41.19
16	1983	Washington Redskins	39.80
17	1977	Miami Dolphins	39.40
18	1991	Washington Redskins	38.55
19	2002	Kansas City Chiefs	38.33
20	1973	Los Angeles Rams	37.69

Bottom 20:

Rank	Year	Tm	OSCORE
1170	1973	San Diego Chargers	-35.44
1171	2000	Cleveland Browns	-35.54
1172	1997	New Orleans Saints	-35.55
1173	1990	New England Patriots	-36.01
1174	2000	Cincinnati Bengals	-36.37
1175	1985	Buffalo Bills	-36.39
1176	2002	Dallas Cowboys	-36.75
1177	1998	Philadelphia Eagles	-37.60
1178	2004	Chicago Bears	-38.34
1179	1977	Buffalo Bills	-38.37
1180	1976	New York Jets	-38.76
1181	1991	Indianapolis Colts	-40.04
1182	2010	Carolina Panthers	-40.35
1183	1972	Philadelphia Eagles	-40.50
1184	1976	Tampa Bay Buccaneers	-40.56
1185	2009	St. Louis Rams	-41.96
1186	1992	Seattle Seahawks	-45.35
1187	2006	Oakland Raiders	-55.49
1188	1974	Atlanta Falcons	-59.13
1189	1977	Tampa Bay Buccaneers	-61.32

Offensive Efficiency: Yards Per Point

This is the fifth part in my series on offensive efficiency. Here are the other four:

O-Score: Measuring Offensive Efficiency (A Preface)

Offensive Efficiency: Yards Per Drive

Offensive Efficiency: Turnovers

Offensive Efficiency: TD% And Points Per Drive

There’s nothing less efficient for an offense than to put together a long, time-consuming, 60+ yard drive and not end up with points. Offenses which can pile up yards but not points are often the same offenses which aren’t good enough at the “little things” to be truly elite units. Here are the 15 best offenses in terms of Yards Per Point since 1970:

You’ll notice that a team’s YPP+ usually correlates to a high Points Per Game (PPG). Noticeably absent from this list of great YPP teams are the Greatest Show On Turf Rams from 2000 and 2001). Here are the best PPG offenses of all time and their YPP:

The 1998 49ers and 1982 Chargers are the big under-peformers here, although still pretty good. Here’s the correlation between PPG and YPP in graphical form:

One thing that sh0uld be mentioned here is that  the average YPP has not changed in the last 40 years:

What this tells us is that all of the changes which have benefited offenses (illegal contact/pass interference rules, defenseless receiver rules, the increase of spread offenses, etc) have not actually made offenses more efficient. In fact, the amount of yards needed to generate a touchdown has stayed remarkably consistent throughout the last 40 years:

On average, a team scores one offensive TD for every ~150 yards of offense it generates.

So what do the best Yard Per Point offenses have in common? Not much, actually. Efficient scoring offenses come in many different varieties. There is no real correlation between a team’s pass/run ratio and their ability to convert yards into points:

There’s also not much of a correlation between a team’s YPP efficiency and their turnover ratio.

There is a correlation, albeit a fairly weak one, between Yards Per Point and Yards Per Play:

Here are the top 15 YPP offenses again, this time with their Pass%, Turnover% and Yards Per Play (Y/P):

And the worst 15 YPP offenses:

Through this series, we’ve seen a number of different ways to evaluate an offense’s efficiency.  Each of them is a piece of the puzzle; the final part of this series will bring all these pieces together into a single metric by which to measure offensive efficiency.

 

Offensive Efficiency: TD% and Points Per Drive

This is the fourth part in my series about offensive efficiency. In case you missed the other three:

O-Score: Measuring Offensive Efficiency (A Preface)

Offensive Efficiency: Yards Per Drive

Offensive Efficiency: Turnovers

Today we look at perhaps the most obvious of all the variables in the discussion of “What Makes An Offense Efficient?”: Touchdown % and Points Per Drive. The goal of an offense should be to score a touchdown on each and every drive. While there are some productive non-scoring drives (the field position scenario I touched on earlier), a touchdown should be the ultimate goal of an offense on every drive except for those where a team needs a FG to win a game in the final minutes. So the best offenses should be thought of as those which score touchdowns the most frequently. Here are the best and worst teams in terms of the percentage of drives which culminated in a touchdown (TD%):

Top 15:

Bottom 15:

Why focus on touchdowns and not overall scoring? A few reasons:

1. In most cases (with the exception of FG attempts at the end of a half/game or in overtime) a field goal attempt is the result of offensive failure. While it’s a better result than a punt or turnover, it still indicates a stalled (i.e. inefficient and/or unsuccessful) drive.

2. Field goals aren’t a sure thing.  A team’s ability to convert FG attempts is dependent upon its kicker. Therefore, a team’s points scored off of field goals cannot be wholly attributed to its offense. Furthermore, a missed or blocked FG can set up an opposing team with great field position – giving them a better chance at scoring. Any time your offense is putting your defense at a disadvantage, you are giving your opponent a scoring advantage.

3. Settling for field goals allows your opponent to outscore you. Any time you score a field goal, you are allowing the opponent a +4 (or 5, if they go for 2) point swing if they convert their ensuing drive into a TD.

That said, the job of an offense is to score as many total points as possible. After all, a failed drive which leads to a field goal is better than failed drive which ends in a punt or turnover. A good stat to measure an offense’s scoring efficiency is their Offensive Points Per Drive (OPPD). Here again are the best and worst Point Per Drive offenses since the 1970 AFL/NFL merger:

Top 15:

Bottom 15:

Now looking at those 4 charts you might notice that for roughly every 1% increase in TD% we expect to see an increase of 1 PPG. Since 1970 there have been 1189 team seasons. In that span, teams have averaged 19.1 PPG and have scored TD’s on 19.5% of their drives. 995 of the 1189 teams fall between .85 and 1.15 PPG per TD%. Here it is in graphical form:

In 2010, the average PPG (combined offense, defense, special teams) was 22. So, an offense which scored TD’s on roughly 23% of their drives should be (on average) a winning team. Here are those teams:

You’ll notice 3 non-winning record teams here: Jacksonville, Dallas and Houston. All 3 teams allowed 400+ points (25 PPG). Noticeably absent from this list were the Jets (11-5), Steelers (12-4) and Ravens (12-4) who were the 6th, 1st and 3rd best defenses (points allowed) respectively.

The next part of this series will focus on points in a different way, measuring the points per yard ratio of a team.

 

 

Offensive Efficiency: Turnovers

In my last post about offensive efficiency I showed that there was a correlation between a team’s offensive points per game (PPG) and their yards per drive (YPD). Since the AFL/NFL merger, teams’ PPG can be shown in this equation:

PPG=0.66(YPD) + .048 with an R² of .6

Now, a lot of things can affect the relationship between YPD and PPG but none more than turnovers. It’s a fairly obvious point: teams which turn the ball over more score less than they should. Here’s the relationship between PPG and turnover percentage (TO%):

It’s not as strong of a correlation as you might think. The R² for this trend line is only .16 which suggests only a small amount of the variation between teams’ PPG is due to their turnover rate. However if we go back to our YPD vs. PPG analysis we see something interesting. Take a look at the all-time best offenses in terms of TO% (i.e. the offense which turned the ball over the fewest times per drive) and how they stack up in terms of expected PPG based on their YPD:

The two columns all the way at the right show the team’s expected PPG based on their YPD, as well as how much they over/underperformed the expected value. The 2010 New England Patriots turned the ball over less than any team in NFL history and ended up scoring 12.28% more points than you’d expect based on historical trends. The top 25 teams by TO% overperformed their PPG by an average of 9.9% and only 7 of the 25 underperformed. Now look at the 25 offenses that turned the ball over the most:

These 25 offenses underperformed their PPG by an average of 11.1% with only 7 of the 25 overperforming. The 2006 Oakland Raiders stand out as one of the most underperforming offenses of all-time, scoring just over half the number of points you would expect based on the number of yards per drive they amassed.  Not surprisingly, they turned the ball over – a lot. 28.57% of their drives ended in a turnover. Not the worst ever, but really bad.

Lastly, here are the best YPD offenses of all time that we saw in the previous post:

What stands out here is that the Greatest Show On Turf (2000 Rams) put up a ton of points but also turned the ball over a ton. How did they manage such a high PPG despite turning the ball over 35 times? Well, they managed to convert an unusually high percentage of their drives (37%) into TD’s – 6th best since 1970. Converting drives to TD’s will be the subject of the next post in this series.

The Effect Of Pass/Run Ratio On Offensive Production

In 1970, the average team threw the ball on just 48% of their offensive plays. In 2010, that number had risen to 56.9%.  The average points per game per team has risen from 19.3 to 22.0. Therefore, the assumption is that more passes = more points. But that’s not necessarily the whole story. Here are the average pass play percentages since 1970:

And here is the average points per game:

As you can see, the increase in points per game doesn’t exactly follow the increase in passing, most noticeably between 1990-1995.

What’s interesting is that there is a strong correlation between pass play percentage and yards per drive:

Over the last 40 years, offenses which pass more than they run tend to generate more yards per drive (YPD). Which makes sense since the average yards-per-attempt is higher for pass plays than it is for rushing plays . In 2010, the average Net Yards Per Pass Attempt [(pass yards-sack yards)/(pass attempts+times sacked)] was 5.7 and the average Yards Per Rush was 4.2.

The trendline is approximately (since we’re dealing with rounded numbers) defined as YPD=14.93(Pass%)+21.01

However, the additional yards gained from passing doesn’t pay off in as many points as you’d think:

Here we see a much looser correlation between the number of pass plays a team runs and the average points per drive (PPD). The trendline is PPD=.111(Pass%)+1.66. Here are the top 20 point-per-drive teams since 1970:

There’s an interesting mix of offenses here. The 2006 Chargers and 2008 Saints had identical PPD but San Diego threw the ball 13.37% less frequently. Four of the top 5 threw the ball less than 60% of the time.

There are a couple things which are going on here. First, teams which score a lot of points tend to run more towards the end of the game to chew up clock (as many of those teams would have built large leads). So they may throw 60% of the time in the first 3 quarters and then run the ball 70% of the time in the 4th quarter. Conversely, teams who don’t score as many points are probably more often in the position where they have to throw a lot to catch up in games – thereby inflating their pass% slightly.

Later this week, I’ll take a look at defensive performance and see if there is any tie between a team’s defensive efficiency and their offense’s pass/run ratio.