Sunday, January 08, 2006

Team Projections

I've finished up my player projections, at least for now. Almost all the good players have been signed. There will be a few more trades, but for most teams I can make a reasonable guess as to what the lineup and roations will look like.

Hitting projections come from the Rally Monkey Projection system. I sum up the major players, and assign a replacement level for the extra outs a team has available. I make sure the playing time is reasonable, in other words Andy Marte and Mike Lowell can't both have 500+ at bats, at least as long as David Ortiz is the DH and 1B time is assigned to Youkilis and Snow.

If I have the lineups, I can also project the defense for all players, using 4 year ZR data with a regression and aging component. That tells how many runs the team will be above or below average, and I use this figure, along with ballpark data, to predict what adjustments to make to each pitchers batting average allowed on balls in play.

My rules for pitching projections is I take the 5 most likely starters and 6 most likely relievers. They aren't allowed to total more than 1425 innings, and if they are under 1425 I assign the extra innings to replacement level pitching. The replacement level differs for each team, it depends on defense, ballpark, and league. Most young starting pitchers have projections for 125-150 innings, while a durable vet is more like 175-200. A team like the White Sox therefore gets more innings assign to starters and less to replacement level pitching. I like this feature.

Once you have runs scored and allowed you can get a team record through the pythagorean formula. I had to adjust runs scored to equal runs allowed, but it was a minor adjustment, my runs scored and allowed, on a league level, were within 4% of each other. I think that's pretty close since they are calculated separately.

I'll post one division at a time.