It’s a subjective estimate, but it nevertheless adds some value, based on our research.
If a team wasn’t ranked in either the Associated Press or Coaches polls, we estimate its strength using the previous season’s final Sagarin rating, reverted to the mean.
When we forecast individual games, we apply a third and final adjustment to our ratings, for travel distance. In extreme cases (a team playing very near its campus or traveling across the country to play a game), the effect of travel can be tantamount to playing a home or road game, despite being on an ostensibly neutral court.
To arrive at our Five Thirty Eight power ratings, which are a measure of teams’ current strength on a neutral court and are displayed on our March Madness predictions interactive graphic, we make two adjustments to our pre-tournament ratings. We review injury reports and deduct points from teams that have key players out of the lineup.
This process might sound arbitrary, but it isn’t: The adjustment is based on Sports-Reference.com’s Win Shares, which estimates the contribution of each player to his team’s record while also adjusting for a team’s strength of schedule.
The reason is that a 30- to 35-game regular season isn’t all that large a sample.
Preseason rankings provide some estimate of each team’s underlying player and coaching talent.
Also displayed in the box for each game is our “excitement index” (check out the lower-right corner) — that number also updates throughout a game and can give you a sense of when it’ll be most fun to tune in.
Loosely based on Brian Burke’s NFL work, the index is a measure of how much each team’s chances of winning have changed over the course of the game.We calculate power ratings for the women’s tournament in much the same way as we do for the men’s.However, because of the relative lack of data for women’s college basketball — a persistent problem when it comes to women’s sports — the process has a few differences: Once we have power ratings for every team, we need to turn them into a forecast — that is, the chance of every team reaching any round of the tournament.The calculation behind this feature is the average change in win probability per basket scored, weighted by the amount of time remaining in the game.This means that a basket made late in the game has more influence on a game’s excitement index than a basket made near the start of the game.So our program won’t assume a player was a monster just because he was scoring 20 points a game against the likes of Abilene Christian and Austin Peay.