Monday, February 19, 2007

Big 10 Rewind: SDPI

One way to look at team strength, taken from Eddie Epstein’s fantastic book Dominance, is to look at teams points scored and allowed relative to the league average and standard deviation. The more standard deviations they are from the mean, the better (or worse they are). For those unfamiliar with what standard deviation is here’s the wikipedia link. In the coming weeks, I will be looking at each Division IA conference and ranking each team in regards to their Standard Deviation Power Index in conference play. Keep in mind, the SDPI does not adjust for schedule strength for conferences such as the ACC where each team does not play each other and it ignores special teams which can play a significant role in both points scored and points allowed.

If you want the meat of the article, skip this next paragraph as it just gives an example of how the SDPI is calculated. The mean points scored and allowed for all Big 10 teams in conference play was 186 points. The standard deviation for points scored was 52.90. The standard deviation for points allowed was 70.08. Penn State scored 135 and allowed 117 points. Penn State's offensive SDPI was -0.96 = ([135-186]/52.90). Their defensive SDPI was .98 = ([186-117]/70.08). Their total SDPI was 0.02. In the 2006 Big 10, that was good for fourth best.

First here's the link to the 2006 Big 10 Standings to refresh your memory.

Now here are the 2006 SDPI Standings.

Ohio State 3.59
Wisconsin 2.11
Michigan 1.68
Penn State 0.02
Purdue -0.30
Iowa -0.31
Minnesota -0.51
Illinois -1.07
Michigan State -1.50
Indiana -1.79
Northwestern -1.92

The 2006 Big 10 was the epitome of football stratification. Ohio State, Wisconsin, and Michigan were head and shoulders above the rest of the league. In fact, the difference in SDPI between Michigan (3rd best) and Penn State (4th best) was greater than the difference between Penn State and Michigan State (9th best).

Best Offense: Ohio State 2.25
Before he melted down in the BCS Championship Game, Troy Smith was a beast in Big 10 play, throwing 20 touchdown passes and just 5 interceptions en route to winning the Heisman. Of course, don't forget the other fabulous skill position players: Antonio Pittman, Ted Ginn Jr., and Anthony Gonzalez to name a few.

Worst Offense: Northwestern -1.15
After averaging 31.6 points per game in Big 10 play in 2005, the Wildcats averaged only 15.6 per game in 2006. Only 3 times did they score more than 10 points (Michigan State, Iowa, and Illinois). Perhaps not coincidentally, they won two of those games.

Best Defense: Ohio State 1.34
Gave up only 92 points in conference play, with 39 coming in the season finale against Michigan.

Worst Defense: Indiana -1.66
5 of their 8 conference foes broke 30 and all 8 broke 20.

Best Team that Didn’t Go to a Bowl: Illinois -1.07
Despite finishing in the Big 10 cellar, the Illini were actually the 8th best team in the conference.

Worst Team that Went to a Bowl: Minnesota -0.51
After a miserable start in Big 10 play (0-5 and outscored by an average of over 20 per game), the Gophers won their final 3 (all by at least 10 points) to become bowl eligible.

Toughest Schedule (ranked by sum of opponent’s SDPI): Northwestern 4.22
Wildcats played the top 6 SDPI teams in the conference and 8 of the top 9. Only way the schedule could have been tougher would be to replace Michigan State with Minnesota.

Easiest Schedule (ranked by sum of opponent’s SDPI): Ohio State -5.40
Played the bottom 6 SDPI teams and avoided Wisconsin. However, their schedule rating is so low primarily because they didn't have to play themselves. Dominated the league, so take their schedule rating with a grain of salt.

Entire Schedule Strength (hardest to easiest)
Northwestern 4.22
Indiana 3.69
Minnesota 3.50
Penn State 2.08
Iowa 1.79
Illinois -0.10
Michigan State -0.30
Michigan -0.31
Wisconsin -4.20
Purdue -4.97
Ohio State -5.40

Team(s) Likely to Decline: Ohio State, Purdue, and Indiana
Buckeyes simply lose too much to repeat as Big 10 champs. Have to go on the road to Michigan and Penn State in 2007. Every 3 years, Buckeyes seem to fall down a notch--2001 7-5 before consecutive 11+ win seasons, 2004 8-4 before consecutive 10+ win seasons. Time for the Boilermakers to pay the piper. After avoiding Michigan and Ohio State in 2005 and 2006, while compiling only 5-6 and 8-6 records, the Boilers get them both to go along with tough road games at Penn State and Minnesota. Hoosiers actually finished tied for 6th in the Big 10 with 3 conference wins, but according to SDPI were actually only better than Northwestern. Despite nearly becoming bowl eligible, Hoosiers have farther to go than most observers believe.

Team(s) Likely to Improve: Illinois and Michigan State
The Illini had terrible luck in close games last season (1-4) and were actually the 8th best team in the conference. Couple that with a few strong recruiting classes and the Zooker will have them back in a bowl game for the first time since their Sugar Bowl appearance in 2001. Spartans were also a tough luck 1-4 in close games so expect some improvement in that area. Also not coached by a complete maniac so they have that going for them.


Anonymous said...

Can you give you reasons for why you think Indiana will decline?

IU has the following in favor of improving in 2007

1) Returns most of their starters from last year,

2) Easier schedule (no OSU or UM)

3) A coach that has proven to be able to mold talent that rivals and scout think of as mediocre.

I'm just curious as to how you think they will decline. I think the 2007 version of Indiana football would beat the 2006 version hands down.

matt said...

In relation to points scored and points allowed, the Hoosiers were closer to the cellar than the conference standings would indicate. Indiana should improve, because they were actually pretty bad last season (especially defensively), but it will not be reflected in their record which should actually decling.

Anonymous said...

I seriously doubt our record will decline. We lost 2 games last year that we should have won due to Hep being sick. Our schedule should be easier.

It's not all about points scored and points allowed. It's how many games you finish with a higher score than the other team.

You also mentioned our SOS as being the 2nd strongest in the conference. Is that considered when making your predictions about who will decline or improve? We played the top 3 teams in the Big Ten this past year but only Wisconsin is on the schedule next year.

matt said...

Your point about the schedule is valid, but the Hoosiers also play two of the teams I think will greatly improve (Michigan State and Illinois) as well as Iowa, Penn State, and Wisconsin.

As far as won/loss record, that is achievement. There is no need for an achievement analysis because its pretty easy to see: how many did you win, how many did you lose. But performance is different. Points scored and allowed tell you a great deal more about how a team performed that won/loss record and is a good indicator of which teams will improve and decline.

Anonymous said...

I'm not too worried about UI or MSU. Zook can't coach even when he has talent.

Anonymous said...

Exactly what makes you think MSU with a first year coach and a team wrecked by attrition will be setting the world on fire? It could happen but I sure wouldn't expect it.

You do follow the SEC right? Did you actually watch the Gators when The Mighty Zooker was there? Illinois was lucky to have stayed close in 4 games. That doesn't mean they'll do it again this year with the B10's worst joke of a coach at the helm. U of I to the cellar again. Take that to Vegas and put the kid's college fund on it.

matt said...

MSU's first year coach is pretty good--check his track record at Cincinnati. They are losing some key players, most famously, Drew Staton. Check the numbers though, Staton didn't set the world on fire last year (4 td passes in 6 conference games). They return their top two runners and their poor record in close games will almost certainly improve.

Anonymous said...

I'll give you that MSU's first year coach has had a pretty good (not Urban good but good) run at another school. It's still his first year and MSU's schedule despite their awful record even by your statistics wasn't all that difficult last year. I expect them to be better but not by a large margin and don't look for their record at the end of the season to show it.

I'm still waiting to be convinced how The Zooker will suddenly turn into a good coach when he had awesome recruiting classes in Florida (which Urban should be sending him thank you cards for) and he still couldn't do better than 7-5. The very next year Meyer showed up Florida came dangerously close to being in the neighborhood of "national powerhouse" good.

IMO watch out for when Champaign tires of Zooker on the sidelines though. Someone will have a heck of a team to take over.