The Vegas Watch Index (AL Edition)

The last few posts have gotten away from the original basis of this site, so I figured I'd go back to its roots with this one.

Over the last two weeks, I have tracked the betting lines for each game at sportsbetting.com. I have used these lines in an attempt to gauge each team's strength.

Each money line can be translated into a percentage. For example, if the Royals are -200 one night (a heavy favorite), that means they need to win that specific game 66.7% of the time to make betting on them a profitable venture.

I took this percentage for every team for every game, and adjusted it slightly, taking away the advantage that is given to home teams (about 3%). After the adjustment, each line is home/away neutral.

I then took the average of each team's percentages from each game over the past two weeks, calculating that team's "Raw" strength.

The next step was to try to incorporate strength of schedule into this. I used a formula similar to college basketball's RPI; 50% team strength, 25% opponents' strength, and 25% opponents' opponents strength. (RPI is 25% team record, 50% SOS, 25% opponents SOS).

The table found below is the Vegas Watch Index (VWI) for the American League from May 21 through June 3. Click here for the National League version.

First off, I would like to say that despite my New York roots, I am not a Yankee fan (far from it).

On a related note, please understand that these ratings have nothing to do with past performance (which, obviously, is why the Yankees can be on top). Like Ken Pomeroy's college basketball ratings, this index is strictly predictive. It measures the strength of a team rather than what they have accomplished.

Although the Yankees' ranking may seem a little inflated, I don't think it's all that out of line. Despite being buried in fourth place, Baseball Prospectus' PECOTA Postseason Odds gives them a 22% chance of making the playoffs (before tonight's loss).

I hate to concentrate so much on the Evil Empire, but I thought that was the most interesting (if not unexpected) thing to come out of the first edition of VWI. The other teams pretty much fall into place- the three first place teams fall into the next three spots.

I will have another post with the VWI for the National League in the next couple days.

Feel free to post in the comments section below. If you have any questions, or just want to tell me I'm an idiot, my e-mail is jnwheat@emory.edu.