[Spraguer]

Thought I would submit something (unsolicited by Bloggy this time!) for discussion.

Here are the formulae that I use to get from raw numbers to lines, if anybody cares.

You need four numbers to work with: visitor runs, home runs, visitor runs allowed, home runs allowed.

Let's take a look at tonight's Yankees/Jays game with Jaret Wright and A.J. Burnett. I've deliberately picked a game that was a no-play for me (I didn't find enough value on either side).

Specifically for tonight's lineups:
I have the Yankees at 5.27 runs scored, 4.64 runs allowed.
I have the Jays at 4.81 runs scored, 4.02 runs allowed.

First, I need "single winning percentages". For this, we first use Bill James' Pythagorean method. The formula is (A^1.83)/((A^1.83)+(B^1.83)), where A is runs scored B is runs allowed. We can do this for each team to figure out the quality they are bringing to the game. The Yankees get a .558; the Jays get a .621 AFTER adding .040 to the Jays' for being at home.

We use another formula of James', Log5, to get from these winnig percentages to probabilities of winning the particular matchup. The Log5 formula is (C-(C*D))/(C+D-((2*C)*D)), where C is the visitors' pythagorean number from the equation above, and D is the home teams'. For the Yankees in tonight's game, I got .435. 1 - .435 = .565, which is the Jays probability of winning.

So, assuming that the four numbers that we started out with (our handicapping) are correct, the Yankees have a .435 chance of winning the game; the Jays have a .565 chance.

So, let's make a line.

The formula is (1-X)/X, where X is the underdogs win probability. So in this game, the equation is (1-.435)/.435 = 1.30. So, the line is 130. Looks better as a dime line, I suppose:

Yankees +135
Jays -125

How much value you need to play is up to you.