Normally I just look at USC data but sometimes it is worth broadening the scope and checking in on the rest of the Pac-10 and looking at the conference overall performance as well. Here are some trend charts from the NCAA database regarding passing offense, rushing offense, and total yardage offense for all ten teams in the conference.
Passing Yards Trend
Here is a snapshot of the passing yardage accumulated by the teams in the Pac-10 since 2001. As you can see the leader in the conference over this time is Arizona State with a four yard advantage over Washington State and about a nine yard advantage over USC for the period in question. Stanford is at the bottom followed by UCLA in 9th place and Arizona in 8th place. I expect the passing numbers out of both UCLA and Arizona will continue to improve the next couple of years due to their offensive coordinators.
In terms of general trends you can see that 2005 was the high mark for the conference with 271 yards per passing on average per team. Of course there is tremendous variation inside that figure with ASU at 373 yards per game and Cal at just 192 yards. Every team was down in 2006 due to the change in play clock rules that season (since eliminated) that shorted games by 10-15% for most teams in terms of plays, drives, and yardage.
USC's average under Pete Carroll is 275 yards passing per game with a high mark in 2005 of 319 passing yards per game. The low points are 2001 and the just completed 2007 season with only 237 yards passing per game. Taking 275 as the standard (seven year trend) for USC then this season was down by about 38 yards on average. In reality that translates to about 3 more completed passes per game when you consider an average of 12.5 yards per completion. Fixing that 3 to 4 pass play gap will no doubt be something much worked on this off season by the coaching staff. Factors that affected the total this year include mainly 1) dropped passes by WR's, 2) poor ball placement, touch, or trajectory at times by the QB, 3) route running and the ability to get open by WR's, 4) the increased prevalence of Cover 4 and 1/4, 1/4, 1/2 pass defense (which generally limits deeper passes more than Cover 2 for example), and 5) any change in the collective pass patterns used by USC this season during the course of games.
Note - Update: February 6, 2008
I went ahead looked at a few more trends for the overall Pac-10 since 2001 out of curiosity. Here are the trends for completion percentage, yards per attempt, and yards per completion.
Pass completion percentage above has improved slightly overall for the conference. In 2001 the figure was 53.79% overall and in 2007 that was up to 57.63% overall. USC leads the conference in this dimension most years and comes in at 62.52%. Oregon university is second at 58.27% with UCLA in third.
The YPA trend is interesting to note in that the average has declined from 7.68 YPA in 2001 to an average of 6.69 in 2007. Just comparing these two data points it is a 12.9% drop off over the seven year period. USC holds a slight lead in this category aided of course by it high completion percentage in the previous category.
Yards per completion is the area where USC ranks the lowest over the past seven years. The YPC figures fell of for USC by an alarming margin in 2007 compared to previous years. I was concerned whether or not that drop off was limited to USC or was a conference wide trend. The amount varies by team and by year of course but overall the conference is facing a period of relative decline of 15.2% in yards per completion comparing 2001 to 2007. I suspect this has to do with improved secondary play, better pass pressure in the conference and the relative rise of Cover 4 and associated pass defenses. Next year will be interesting to watch in this regard.
Rushing Yards Trend
Here is the rushing trend for USC and the rest of the Pac-10 over the same period of time. The top three rushing teams are Cal, USC, and Oregon. Oddly the first two are probably more noted for their passing game but both Pete Carroll and Jeff Tedford strive for balanced effective running games as well. The bottom three rushing teams are Arizona, Stanford, and Washington.
In terms of general observation for the Pac-10 2005 was again the high point for the conference followed closely by this past season. 2006 not surprisingly was among the lowest but edged out by 2002 and 2003 seasons.
USC's rushing performance picked up nicely in 2007 after a poor 2006 season when a relatively new offensive line, freshman running backs, and no healthy experienced fullback all resulted in a drop off to just 128.0 yards per game. This past season with a more experienced line, more experience at running back and a healthy Stanley Havili the average jumped up to 197.2 yards and the second best mark of the Pete Carroll era. Next year will be an interesting one to watch in terms of rushing yards. A relatively new offensive line will start but strong experience at tailback will return in Stafon Johnson, Joe McKnight, CJ Gable and others. With a new QB starting next season defenses will probably gear up more to stop the run at least in the early part of the season. Perhaps that will have some positive spill over effect for the passing game next season.
Total Offense Trend
Adding the two boxes from above you get the final result tabulated below for the Pac-10 overall. No surprise that in the total offense comparison USC rises to number one followed by Arizona State and then Washington State. The bottom three teams over the past seven years on average from the bottom up are Stanford, Arizona, and UCLA.
In terms of overall Pac-10 trends 2005 was the high point for the conference with 433 yards per game on average. That figure plummeted the next season down to 347.8 with lesser talent and shorter game clock rules. 2007 was a more normal 394.9 yards per game.
USC finished 2007 with 434.9 yards per game on offense. In just the ten games that John David Booty started this season the figure averages out to slightly better or 453 yards per game. Both numbers are right at the 440.2 yards for the overall Pete Carroll era. The 391 yard mark in 2006 in reality is more like 430 yards when adjusted for the effect of fewer plays and fewer drives that season. Next year should be good offensively for USC as well but there are significant question marks to be answered at the QB position, WR spots, and the offensive line positions.
