Tuesday, November 13, 2007

The BCS Computer Rankings

In doing my Power Rankings I was curious as to where our ranking system compared to the “computer” ranking systems that contribute to the BCS standings. The following grid shows Saurian Sagacity’s Power Rankings as compared to the six BCS computer ranking systems –

Don't strain your eyes -click on it

As you can see, we aren’t that different at the very top. LSU is the consensus number 1 among the computer rankings, and number 1 in ours. Oregon, our second ranked team, is either 2nd or 3rd in each computer ranking.

Billingsley is the only system with Ohio State higher than our ranking of 3rd (they have them 2nd). Our 4th team in Missouri ranges anywhere from 5th to 10th (though mostly around 5th), while our 5th team in Kansas is 1st in two rankings, and no worse than 6th.

We have Florida higher at 6th than any other computer ranking (with an exception to be noted in a bit). Florida is pretty strongly ranked though for a 3 loss team by the computers, ranging anywhere from 7th to 15th.

South Florida, our surprise 7th ranked team, is treated better by the computers than it is by the humans. Unranked in either the AP or Harris polls, USF is 15th in Sagarin’s system, and 18th in the Colley Matrix.

The rest of our Power Rankings are pretty uncontroversial, with virtually the same teams ranked in some order as the other computer ranking models, with the exceptions of maybe our inclusion of Rutgers, and our exclusion of Southern Cal. USC is strange case in the computer rankings, as high as 7th in Billingsley, and as low as 18th in the Colley Matrix and Massey Ratings.

The computer contribution by Sagarin is actually his less favored of his two systems he posts on his site.

On his site in the notations about his system, Sagarin’s states, almost sarcastically, that in the ELO_CHESS as used by the BCS “only winning and losing matters; the score margin is of no consequence,which makes it very "politically correct". However it is less accurate in its predictions forupcoming games than is the PURE POINTS, in which the score margin is the only thing that matters.”

Which leads us to Sagarin’s current PREDICTOR rankings (used by our own Henry in his Sagarin v. Vegas columns) –

In many ways, Sagarin’s PREDICTOR looks a lot like our own Power Rankings. Not only does it rank Florida the same as we do at 6th, it has South Florida ranked higher than any of his computer peers at 11th. (Of course, according to Sagarin’s PREDICTOR, Florida would beat Georgia by 9 points in a game played at a neutral site. I witnessed just such a game, and I don’t believe it.)
Did we somehow stumble onto a system that in many ways mirrors Sagarin’s? As he is unwilling to release his methodology, we can’t know for sure, but his systems must heavily rely on a strength of schedule component (as does ours). In making the 6th ranking in Sagarin’s system, a 3 loss Florida shows a schedule with a 2nd overall ranking. Likewise, 11th ranked USF is said to have the 16th hardest schedule, which undoubtedly propels them into that high ranking.


jimcaserta said...

The fact that DII NE Omaha made it into Massey's top 25 means there is a serious algorithm problem. Even if you just eliminate those teams, that doesn't fix the problem with his code/inputs.

Now if Kentucky can just win out...

dethwing said...

The reason Billinsgly ranks OSU and USC so much higher than everyone else (Boise too) is that he uses a pre-season poll. His results from last year cary over to this year. For this reason alone his rankings should be stricken from the BCS. It's unconsionable to me, to use data from seasons beyond the one we are in. No one else seems to care about this agregious conduct though.

Anonymous said...

why does the bcs use computer rankings that it does not know the equations to (sagarin, etc)? do they have some kind of contract that he will use the same formula week to week, because if he sent in his bottom 25 instead of top 25 i don't see how they could just take his ranking out of the formula.

Gator Duck said...

I have a problem with all the computer ratings, including Saurian's. The problem is that Ohio State, which is ranked higher than Florida, plays a weak schedule. Their SoS is only 31st and the Gators' is 2nd. Yes, Florida has 3 losses compared to OSU's 1, but OSU still has only played 1 ranked team all season!

It is all a bunch of bullzook. The bucknuts say the Gators win was an anomaly. Well, even with the problems on defense the Gators have had this year, I'd love to see a rematch.