This week's games: BYU at Tulane

It is not often that the Green Wave get to host the number 9 team in the country, and to be only 17 point underdogs has to be encouraging. After playing with nothing to lose a week ago, BYU is now playing with the weight of the world on its shoulders. AP voters took a big gamble in voting the Cougars up 11 spots. And BYU might be tempted to look ahead-when Florida State comes to town it will be the biggest game in Provo that didn't involve the Utes in a very long time. With a few guys at ESPN talking BCS and even national championship game, Max Hall and Co. will need to work hard to stay focused on day to day tasks. The Tulane program has been on a downward slide since Katrina, though, and shouldn't prove too tough a test for BYU.

This week's games: Notre Dame at Michigan

Considering that these two teams have hit new historic lows the last couple of seasons, this game is absurdly attention grabbing nationally. But it warrants the attention. First, it is the undercard of a weekend that will make or break the Big 10. Wins by the Wolverines and Buckeyes would catapult the Big 10 out of pee-wee league status. We also have two coaches that are on the ropes and need to win early and often. And both teams looked they were ready to do just that after impressive debuts.


Michigan's offense is much improved from a year ago (watching Sheridan and Threet do their best Pat White impressions was always good for a laugh). And a much maligned defense underperformed relative to its talent last season, and showed signs of moving in the right direction against Western Michigan. But this Michigan team, like last year's, is too prone to mood swings, and a hostile crowd at home just exacerbated that last season. Consequently, the first 10 minutes of this game will be crucial. If Clausen-to-Floyd gets rolling early (and I think it will), it could be a very long day for the blue-and-gold with silly mistakes, schematic breakdowns, and lackluster effort. On the other side, it will come down to speed-does Notre Dame field enough speed to keep Robinson from breaking a long touchdown? If so, Notre Dame will cover its 3.5.

cRPI goes for baseball too

In the spirit of the season, I've ranked MLB teams using the cRPI. I only had data for 2007, so its a bit antiquated, but it does demonstrate some of the advantages of the cRPI.

For example, from the more competitive east, the Ray, Red Sox and Yankees are 3, 4, and 7 by winning percentage, respectively, but are 2, 3, and 5 by cRPI-a more accurate assessment of their performance.

CB: RPI sucks; Enter the cRPI

Since 1981, college basketball fans and selection committees have suffered under the tyranny of the Ratings Percentage Index (RPI), perhaps the worst rating system in all of sports.

And why, you might ask, is the RPI such a waste of intellectual effort? Quite simply, it violates the first law of rating systems: If we are to only consider wins and losses (which is a mistake, but politically correct), we should never penalize a team for winning, regardless of the quality of the competition. Any time a team plays they risk losing-and a meaningful rating system should reflect that. The RPI seems to believe that beating NJIT somehow makes your team less deserving, and that's a load of crap.

So, out of respect for sports of all ball shapes and sizes, I have corrected the RPI. Consistent with the philosophy of the RPI, the cRPI only considers wins and losses, opponent's winning percentage and opponent's opponent's winning percentage-but it is a much more valid reflection of reality.

The cRPI looks a bit more complicated than the RPI, but it really only requires one extra step to calculate. It uses products instead of sums and logs instead of more sums, but its all the same to a computer.

So, how does the cRPI perform. First, I correlated the cRPI, the RPI and a team's winning percentage. A common, and valid complaint, against the RPI is that a team's winning percentage makes up only 25% of the equation. At r=.86, the correlation is actually quite high, but not as high as .96, the correlation between winning percentage and and a team's cRPI.

But the RPI also accounts for strength of schedule. The cRPI and RPI would use the same SOS metric, but use them in different ways. To compare the two, I have compared to two scales to the AP poll as of March 9. The cRPI rank correlates with the AP poll at r=.82 while the RPI rank correlates at only .69. My corrected RPI not only does not undervalue winning, but it is a significantly better reflection of how people judge teams.

the cRPI also has some real nice additional features-it is completely decomposable, it will tend to approximate a normal distribution at both the national level and in the sampling distribution of individual teams, and, relatedly, it can be used for statistical testing and setting rough odds for a game outcome. The link below connects to the complete rating and ranking of the 340 some division I college basketball teams.