Here is some material I have been working on part time for a few weeks since the season ended. It took a while to pull all the data together and make sure things added up. Finally it seems complete enough to compile into a summary post. The following paragraphs look at USC football points production and will attempt to highlight the points scored by the Trojans over the past few years as well as the main sources of variation. I did not fully include 2001 and 2002 in this study since the scoring drive charts were not all posted on-line by USC's Athletics Department for each game. For the few games I sampled however the same trend that I will explain below held true. (Note: I have looked at this topic before but this supersedes any previous data posted here and should be more accurate and thorough).
First let's start at the highest level that fans look at during the course of a season of when checking the sports page or NCAA website. Here is USC total points production over the past seven years.
| 2001 |
2002 |
2003 |
2004 |
2005 |
2006 |
2007 |
Average |
| 26.55 |
35.77 |
41.08 |
38.15 |
49.08 |
30.46 |
32.62 |
36.24 |
The lowest year is 26.55 points per game back in 2001 during Pete Carroll's first season as head coach. The highest is of course the 2005 season at 49.08 points with the Matt Leinart, Reggie Bush, LenDale White, Steve Smith, and Dwayne Jarrett star studded line up as well as of course an amazing offensive line. The average points per game scored is 36.24 over the seven year span and the past two years have been on the lower side. (Note: the 2006 season was effectively 10% shorter due to changes in the game clock rules. I will not adjust for that effect but any cross year comparison should probably bump those figures up by roughly that amount.)
The only problem with looking at the data at this level however is that the total combines so many different factors it is hard to sort out for study in terms of the sources of variation. For example in football,
a) The defense scores points at times on safeties, interceptions or fumbles recovered for touchdowns
b) Special teams units score points on punt and kick off returns for touchdowns
c) Teams score on offense at a higher percentage after turnovers by the defense
d) Teams can score on short field scores (less that half the field) after blocked kicks, or turnovers, or excellent kick returns
e) Teams can score starting from normal field position starting around the 30 yard line
f) Teams can score marching the length of the field (85 to 90 yards or more)
Each of these categories is indicative of a different strength or weakness in a given year. The first several categories (a, b, c, and d) for example are reflective of how defensive and special teams play directly and indirectly contribute to scoring by the offense. The latter cases (e, and f) are more reflective of the true offensive capability in my opinion since those involve sustaining drives the length of the field. It is worth looking at each of these closer in detail for greater insight into how an team actually scores. For simplicity I chose to break things into the five categories listed below instead all the ones listed above.
When you put the USC scoring drives into the following categories for the years 2003 to 2007 the following picture emerges for the number of raw scores (i.e. all TD's FG's, Safeties, etc.). Category 1 = Defense or Special Teams Scoring. Category 2 = Scores on offense after a turnover (TO) caused by the defense. Category 3 = Other scores (Non TO related) on short field (SF) drives starting on the opponents 1 to 50 yard line. Category 4 = Medium field drives for TD by the offense without the benefit of turnovers and starting between the USC 21 and 49 yard line. Category 5 = Long field drives for TD by the offense without the benefit of turnovers and starting between the USC 1 to 20 yard line. Here is the five year summary:
| Category | Scoring Explanation |
2003 | 2004 | 2005 | 2006 | 2007 |
| 1 | Defense or
Special Teams |
11 | 3 | 4 | 3 | 0 |
| 2 | Scores off TO's | 18 | 22 | 22 | 12 | 18 |
| 3 | Non TO SF drive (1-50) | 12 | 9 | 10 | 4 | 9 |
| 4 | Non TO MF drive (49-21) | 26 | 37 | 28 | 32 | 28 |
| 5 | Non TO LF drive (20-1) | 22 | 9 | 34 | 15 | 15 |
| Sum Total | 89 | 80 | 98 | 66 | 70 |
Converting the data into points it looks as follows:
| Category | Scoring Explanation |
2003 | 2004 | 2005 | 2006 | 2007 |
| 1 | Defense or
Special Teams |
5.1 | 1.6 | 2.1 | 1.7 | 0.0 |
| 2 | Scores off TO's | 8.1 | 10.0 | 11.2 | 5.8 | 8.1 |
| 3 | Non TO SF drive (1-50) | 5.2 | 4.2 | 4.7 | 1.8 | 4.5 |
| 4 | Non TO MF drive (49-21) | 11.8 | 17.8 | 14.1 | 13.5 | 12.9 |
| 5 | Non TO LF drive (20-1) | 10.9 | 4.5 | 17.0 | 7.7 | 7.1 |
| Total | 41.1 | 38.1 | 49.1 | 30.5 | 32.6 |
As you can see the totals move around a bit and are pretty interesting once you start comparing the sections with each other across time. I will put them into chart form for easier viewing and explanation purposes. Let's start with Category 1 - direct scoring by either the defense or special teams.
The numbers are not large but they are still significant. The 2003 edition of USC football for example was amazing in that the defense and special teams scored almost a dozen times in one season without the offense ever taking the field. There were 2 safeties as well as 5 interceptions returned for TD (Will Poole, Lofa Tatupu, Jason Leach, Ronald Nunn, and Omar Nazel one each). In addition there were 4 fumbles returned for touchdown (2 by Mike Patterson, and one each by Ronald Nunn, and Kenechi Udeze). That accounts for 67 points of the USC total scoring offense that season or 5.1 points per game on average. Each season afterwards has scored fewer points in this manner and 2007 was the first team of the Pete Carroll era to be shut out on defense or special teams. Even last season in 2006 Brian Cushing scored versus Notre Dame on an on-side kick off return and Terrell Thomas scored versus Stanford on a blocked kick for example.
Of course direct scoring by the defense and special teams is one thing but contribution of good field position and positive momentum is another to be considered. In the Rose Bowl game the network put up the following picture in the game in the 4th quarter.
Teams tend to score more often after turnovers for a couple of reasons. Number one is simply field position. The average spot over the past few years after USC creates a turnover is roughly the opponents 40 yard line. The offense starts with a short field and only has to move about 10 yards to get into field goal range and 40 yards to score a touchdown. USC is about 70% likely to score from such a spot the last time I checked. That effect can not be ignored. Combining the points in the first row from above (direct scores by defense and special teams) along with points scored after a turnover the past five years you get the following result for categories one and two.
As you can see that is a pretty interesting insight. A very significant amount of USC scoring in any given season is a product of either direct scores, beneficial field position, or the momentum created after turnovers by the defense. This result becomes important when you also consider the trend the past several seasons for USC football in terms of turnover margin (see below).
For this turnover trend data I'll go back to 2002 since the information is easily obtainable. The blue columns indicate the turnovers forced on defense by either fumbles or interceptions. The middle bar is the number committed by USC on offense. The third and lightest colored bar is the differential for the year (i.e. turn over margin). Quite disturbingly turnovers forced by USC have fallen the past two years while turnovers by the offense spiked in 2007. The turnover differential has been extremely small for two seasons now. That may sound insignificant but remember that the average field position after a turnover is the opponents 40 yard line for USC. From 2002 to 2005 that meant 38 to 42 drives per year that started *on average* inside the opponents half of the field. From there USC is highly likely to score (roughly 70%). When there is no turnover USC gets the ball back on a punt for example and loses 40 or so yards of field position and starts around or inside its 20 yard line. When USC commits a turnover it in turn gives the opponent a shorter field to work with as well. That net effect is large and troubling when I look further at the data.
Of course even where there is not a turnover USC often gets a nice kick or punt return or the on occasion the opponent shanks a punt, etc. to help field position. Those instances also give USC short field position in a variety of subtle ways. I calculated those separately as Category 3 from the table above. Adding up rows one through three above now will give a complete total of short field (less than 50 yard drives), as well as points after turnovers, and points directly scored by the defense. The trend now starts to become somewhat alarming when these three components are added together. As you can see below the offense the past two years clearly has not benefited from short field scoring opportunities as much as it has in previous years. (Note: I sampled four games for 2002 and it was roughly the same picture.)
Next here is what is left over when you strip away the first three categories and see what the offense can do when it starts on its own side of the field and has to travel at least 50 yards to score and does not have the sudden momentum change advantage of a turnover. The following chart is Categories 4 and 5 put together. In my opinion this is the most accurate measurement solely of offensive points capability since it nets out most of the help often provided by special teams or defense. The result is pretty flat across four of the years and of course still spikes upward for the amazing 2005 USC offense. The 2006 figure might be bumped up a small amount as I mentioned above due to the scoring clock rules as well.
If you look at the breakdown in terms of points scored by USC as organized above the following trend pops out that I mentioned above. The biggest problem the USC offense has had the past two years in terms of scoring has mainly been a decline in short field scoring opportunities which in reality are created as much or more by defense, special teams, and other events. That message might seems somewhat perplexing at first but here are some additional points to keep in mind that tend to back it up overall.
For starters 3rd down and 4th down conversion percentages have been improving overall the past seven years. The 2005 squad was of course the best but the next two best seasons have been 2006 and 2007 by a slight margin. 4th down conversion exhibits a somewhat similar trend.
Here is a look at the average drive length by USC the past few seasons. This is calculated by taking all the yards for a given season and dividing it by the total number of drives for the year. I did not sort the data and pick out the one play kneel downs etc. before halftime or the end of the game. So this probably understates the "real" number by a slight margin and may affect a couple years more than others but the effect should be small (i.e. a yard or two at most).
Average yards per play over the seven year provides another insight that I think is more revealing in terms of the total picture. USC was better on offense in the years of 2003 to 2004 by about a half yard per play and of course a larger amount in 2005. Those years correspond with the development of Reggie Bush, Matt Leinart, LenDale White, the WR's and one of the best offensive lines in recent USC history. The years of 2002, 2006, and 2007 have indeed been more "ordinary" compared to those years.
So in summary back to where we started up top above with total points. If you want to see an increase in points scored per game by USC there are multiple ways for the Trojans to accomplish the goal. For one the defense and special teams could come though again and score some points directly which I think is unlikely given the past two years. 2003 in reality probably was unique in that regard. Additionally however the defense can contribute in a major way by producing the same level of turnovers accomplished in years 2001 to 2005. That would dramatically help field position and increase the probability of any given scoring drive. The last option of course is for the offense to become more explosive in terms of big play potential or increase the number of long field drives that result in scoring. With skilled players such as Joe McKnight and Stafon Johnson at RB and many other talented receivers returning that may be possible. However the unknown variables at this point in time for USC are of course 1) the QB position, 2) the depth and talent of the 80% new offensive line, and of course 3) the inevitable injuries and position shifts that will occur, etc. With no up tick in turnovers and short field positions scores however I suspect USC will remain "stuck" around the level of 32 points per game. That level is nothing to sneeze at but it feels slightly low compared to the past several seasons (a sign of how spoiled we have become?). I'll check this again at the end of 2008 to see how things differ in another 12 months. Either way I hope the points situation improves for USC or at least the reasons why become clearer in the upcoming season.