Forecasting
Well, Billy Beane is believed to have perfected it…forecasting the performance of a player and, to GM’s and those of us in auction leagues, value.
MVN blogger Jake Berlin in “The Bard’s Room,” the White Sox site here on MVN, recently posted “Regression,” referencing Tangotiger’s 2007 Marcel Projections. Essentially, one can download projections on how hitters and pitchers will do during the 2007 season.
I also came across an old link to Ron Shandler’s Baseball Forecaster site, and his article, “The Great Myths of Projective Accuracy.” Shandler notes:
But through all their fine efforts at attempting to predict the future, there have been certain constants. The core of every system has been comprised of pretty much the same elements:
* Players will perform within the framework of their past history and/or trends.
* Skills will develop and decline according to age.
* Statistics will be shaped by a player's health, expected role and home ballpark.
These are the elements that keep all projections within a range of believability. This is what prevents us from predicting a 40-HR season out of Juan Pierre or 40 SBs for David Ortiz. However, within this range of believability is a great black hole where any semblance of precision seems to disappear. Yes, we know that Albert Pujols is a leading power hitter, but whether he is going to hit 40 HRs, or 45, or 35, or 50, is a mystery.
You see, while all these systems are built upon the same basic elements, they also are constrained by the same global limitations. We are all still trying to project...
* a bunch of human beings
* each with their own individual skill sets
* each with their own individual rates of growth and decline
* each with different abilities to resist and recover from injury
* each limited to opportunities determined by other people
* and each generating a group of statistics largely affected by tons of external noise.
So what does this mean for Brewers’ GM Doug Melvin and skipper Ned Yost in determining who to play, and when, for the 2007 season? First, every Brewers’ hitter will be affected, somewhat, by the change to Jim Skaalen as the hitting coach. Skaalen will start from scratch in looking at the swing, the stance, and probably even the bat weight. Then, as Shandler noted, some players have increased their mental and physical abilities, while others likely have seen at least their physical abilities decline, or at least change–e.g., J.J. Hardy may approach his pre-season training differently as the result of his injury last season, thus over emphasizing some muscles, while favoring others. Of course, the pitchers’ stats and performance this season will no doubt be impacted by seeing Alfonso Soriano 14+ games this year versus half that last year…not to mention seeing former teammate Carlos Lee; Jeff Suppan will have to face Albert Pujols and the Cardinals this year instead of the Milwaukee Brewers…and we know Derrick Turnbow will get a lot less saves than last year.
Of course, there are daily variables as well…not only who the batters will be facing on any given day (and that pitcher’s set of changes), but also, in Milwaukee’s case, whether or not the roof is open or not and, if not, what the wind velocity, wind direction and humidity are. Even a player’s second AB against a pitcher has a whole new set of variables: the pitcher’s thoughts on what the hitter did in his first AB, the hitter’s adjustments based on what he saw during his first AB, and, of course, differences in pitches based on how many baserunners are on base, what the score is, and how many outs there are.
What’s this all mean? Hey, maybe Geoff Jenkins might be a .300 hitter this year!
David Hannes
Copyright 2007





2 Responses to “Forecasting”
January 16th, 2007 at 10:20 pm
Good post, David. I think even Nate Silver, purveyor of the PECOTA system which has been 78% accurate (!!!) over the past several years, who is very proud (and rightfully so) of his work would admit that there are far-reaching limitations to forecasts. PECOTA can’t predict what twists and turns wil take place in the upcoming season, but it does account for a hell of a lot of variables. It is really quite accurate in saying “if this1 this2 and this3 then that1 and that2″ — it’s when this1 and this2 don’t happen that things get screwed up, mostly. Don’t bet your livelihood on a projection system (even PECOTA), but it can’t hurt to hear what they have to say, expecially for you fantasy drafts.
January 17th, 2007 at 5:42 pm
I’ll have to check that out…thought I was pretty good at it last year, having started out 8-3 and tied for first-place in all of the first eleven weeks of the season; went 5-6 in the second half, finished sixth…biggest blunder was cutting Chien-Ming Wang for John Rheinecker…eventual champ picked up Wang and rode him to the finish line. I drafted Geoff Jenkins, too, and held onto him for 5-6 weeks…wound up cutting him for Gary Matthews, Jr. (yes, he was still available)…I must have had the highest Beta team in the history of fantasy baseball–I had two weeks where I scored over 100 points, but at least two other weeks where I scored fewer than 50 points.
Jenkins, theoretically, could have a comeback season…some new factors:
1. It is the last year of his contract…I’ve seen one study that did show that players’ in the final year of their contract tend to do better than the year before.
2. We’ve got a new hitting coach that Jenkins might actually listen to.
3. If he starts, he’ll likely be platooned and sit versus left-handed pitchers…that alone could drive his average up into the .280 range.
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