This is the sixth in a series of posts that will review the 2009 season (as well as 2008) from an adjusted stats perspective.
Tentative Publication Schedule
Part I: Which Stats Correlate Best to Winning? - 6/24/10
Part II: Drilling Down and Regression Models - 6/28/10
Part III: Passing Efficiency Formula - 6/30/10
Part IV: Conference Strengths and Pace - 7/2/10
Part V: Testing Conventional Wisdom - 7/16/10
Part VI: Team Matchups - 7/20/10
Part VII: Year-to-Year Changes - 7/22/10
Part VIII: Points per Yard Efficiencies - 7/26/10
Part IX: Data Dump - Team Rankings - 7/28/10
Part X: Data Dump - Team Reports - 7/30/10
Thus far our studies have focused on season performance as a whole. But if we want to analyze matchups then we have to look at things on a game-by-game basis. Before getting into matchups of individual units, let’s look at the highest level possible. On a single game basis, does being the higher scoring team or the team that allows fewer points lead to wins more often? How about offensive and defensive strength on a yards per play basis? This post will use only adjusted stats:
|Pts All. per Game||546-168||0.765||518-199||0.722||1064-367||0.744|
|Points per Game||527-187||0.738||533-184||0.743||1060-371||0.741|
|Yards per Play||488-226||0.683||493-224||0.688||981-450||0.686|
|Yards Allowed per Play||495-219||0.693||482-235||0.672||977-454||0.683|
Not surprisingly, offense and defense show nearly equal performance in this analysis. Hopefully at this point nobody is surprised to see such a result. But we haven’t controlled for offense versus defense. Let’s rerun the analysis based on whether the same team has both matchup edges.
|Both Points Edges||399-40||0.909||396-63||0.863||795-103||0.885|
|Both Yards Edges||324-55||0.855||322-64||0.834||646-119||0.844|
|Off. Yds, not Def. Yds||164-171||0.490||169-159||0.515||333-330||0.502|
|Off. Pts, not Def. Pts||128-147||0.465||135-120||0.529||263-267||0.496|
Yet again, there is no new information to be gleaned. Having the offensive edge is roughly as advantageous as having the defensive edge. Teams that have the edge on one side but not the other are 0.500 against each other. At this point I lack any motivation to come up with new ways of comparing offensive to defensive importance. While intuitively I used to think that defense may be slightly more important than offense because a team’s defense can score without any input from the offense, the numbers aren’t bearing that out. The values for scoring edges above aren’t what I base that on as they include defensive scores for a team’s offense, but instead the yardage results reinforce each side of the ball’s equal importance. It’s worth considering that while a defense can score on their own, an offense has given up those same points on their own.
The next level for this analysis is to look at the individual units. We’re back to the run game versus pass game debate, but this time will we find some statistical backing for the widely held belief that being able to run and stop the run is more important to a team’s success than the passing game? First things first, let’s look at the overall numbers based on having the matchup edge in each individual statistic (comparing offense to offense and defense to defense):
|Tot. Passing per Att.||495-219||0.693||502-215||0.700||997-434||0.697|
|Tot. Passing All. per Att.||498-216||0.697||472-245||0.658||970-461||0.678|
|Tot. Rush. All. per Carry||480-234||0.672||462-255||0.644||942-489||0.658|
|Tot. Rush. per Carry||450-264||0.630||431-286||0.601||881-550||0.616|
Well we haven’t found the statistical evidence to support the run game proponents yet. While it’s good to have a run game advantage over your opponent on either side of the ball, neither matches the advantage gained by being better at throwing the ball or defending your opponent’s throws. Something else that has popped up again is the recurring theme that being able to stop the run is more important than being able to run the ball. This was true in our first correlation studies and has been reaffirmed here. Next is the table showing the performance based on having both or just one edge while still keeping the pass and run games separate.
|Both Passing Edges||347-68||0.836||329-72||0.820||676-140||0.828|
|Both Rushing Edges||299-83||0.783||278-102||0.732||577-185||0.757|
|Off. Pass, not Def. Pass||148-151||0.495||173-143||0.547||321-294||0.522|
|Off. Rush, not Def. Rush||151-181||0.455||153-184||0.454||304-365||0.454|
The pass game still rates as more important than the run game (top two rows). Additionally, being able to defend the run also continues to reveal itself as more important than being able to run the ball. The only slight surprise with these results is that being able to throw the ball appears more important than being able to defend the pass. Previously these two aspects of the game have shown themselves to be essentially equally important. And in this case we see that 2009 did show an even relationship but 2008 did not. With only two seasons to view, it’s possible that 2008 was merely an outlier.
So far we’ve been comparing a team’s offense to their opponent’s offense and their defense to their opponent’s defense. But we know that the true matchup lies in the interaction between one team’s offense and the other’s defense. When looking at these two phases, there are four matchups in each game – two passing game matchups and two running game matchups. In order to determine the winner of each matchup I used the normalized ratings. This makes it possible to compare one team’s rating in an offensive statistic with their opponent’s rating in the defensive equivalent. On the next page is a table showing the win-loss performance of each possible permutation of these matchups. Keep in mind that each row shows two permutations. For example, the success of teams that win all four matchups is shown in the first row at 365-39 overall for the past two seasons. Therefore teams that have lost all four matchups are obviously 39-365 over that time period. Also, scenarios where one team wins both their offensive matchups but loses both their defensive matchups are left out because their record will necessarily be 0.500 in those situations (if Team A wins both offensive matchups but loses both defensive matchups from their perspective then Team B is in the identical situation from their viewpoint). The same logic explains why scenarios where one team wins their offensive passing and defensive rushing matchups but loses their defensive passing and offensive rushing matchups are not shown.
|Win All 4 Unit Matchups||194-18||0.915||171-21||0.891||365-39||0.903|
|Win 2 Pass. (Rush. Ign.)||349-66||0.841||312-78||0.800||661-144||0.821|
|Win 3, Lose Off Rushing||83-17||0.830||65-19||0.774||148-36||0.804|
|Win 3, Lose Def Rushing||52-14||0.788||45-13||0.776||97-27||0.782|
|Win 2 Rush. (Pass. Ign.)||293-84||0.777||277-110||0.716||570-194||0.746|
|Win 3, Lose Off Passing||47-18||0.723||40-30||0.571||87-48||0.644|
|Win 3, Lose Def Passing||35-28||0.556||41-28||0.594||76-56||0.576|
|Win 2 Pass., Lose 2 Rush.||20-17||0.541||31-25||0.554||51-42||0.548|
We’ve now tortured the data in about every way possible regarding passing versus running the ball. There doesn’t appear to be any way to run the calculations that will support the argument that being able to run the ball or stop the run is more important – or even as important – as being able to pass the ball and stop the pass. The data simply does not support that line of thinking.
With that said, this doesn’t necessarily serve as an argument to completely ignore the run game. Each team has to maximize their ability in the context of their personnel and their opponents. Passing every down may decrease a team’s passing effectiveness such that it hampers their overall scoring pace. Recall that these analyses have been done using total passing per attempt, not per game. Maximizing efficiency through the air and minimizing the same for opponents is the best approach to winning more games. For some teams in some seasons a bigger commitment to running the ball may yield only a small increase in total rushing per carry with an even more negligible direct effect on their win probability. But if that commitment opens up the passing game and improves their production through the air then it will lead to more overall success.
Thoughts and comments welcome as always.