- Oct 27, 2012
Here is this week's AP poll and a comparison to three popular ranking system: Sagarin, Sagarin-Elo, Pomeroy and an average of all three. I suspect most (credible) ranking systems are fairly close to these three so it should be fairly close to the true disconnect between human polls and computer rankings.
In my opinion, if a voter is not close to an objective system, it is a clear indication of bias and/or conspiracy to maximize profit via top-25 matchups. There is no stronger evidence for this than the fact that Louisville, Duke, Florida and Kentucky all get a pretty significant bump from both the average and median of these three computer systems.
As can be seen from the R2 values, the predictive systems (Pomeroy and Sagarin) are slightly closer to the AP poll than the Elo, which is interesting because Elo is based on the actual outcome of the games. Since there's no real accountability, a voter can pick and choose which system (predictive vs what a team has accomplished) to move teams around but still have an objective system to use as evidence for their ranking. So a voter could put Duke at 15 because they are very efficient (high in Pomeroy, but low in Elo) but put UMass at 20 because they are not as efficient as Duke even if they have a better resume.
It is quite ironic that the numerous objective ranking systems originally inspired to combat subjective human pollsters may be actually be increasing subjectivity by giving voters such a wide range of empirical evidence to draw from.
The most overranked teams include:
Louisville (12), Duke (18) - 5 spots higher than 3-system average
Florida (6), San Diego State (7), UMass (13)- 8 spots higher
Kansas State (22) - 9 spots higher
Memphis (23) - 10 spots higher
Kentucky (14) - 11 spots higher
Baylor (24) - 20 spots higher
Some underranked teams are Iowa(10) at four spots lower, Pittsburgh (20) at seven spots lower and Michigan (21) also seven spots lower.
It makes you wonder why Baylor is still clinging to a top-25 ranking (maybe the game with Kansas tonight ... more eyeballs for a "top-25" matchup?) even though they are in the 40s for each system. Obviously the big-time basketball programs get a bump (Louisville, Duke, Florida, Memphis, Kentucky).
Even something has seemingly inconsequential as a weekly poll in college basketball manages to get corrupted by money.