Three True Outcomes/Sim

[mickeyg13]

So I've been trying lately to develop some software to simulate baseball games. However, I've run into an issue that I can't decide how to resolve. In case you weren't aware, Voros McCracken of Baseball Prospectus fame has put together some decent arguments that pitchers have little, if any, ability to prevent base hits on balls hit within the field of play (excluding home runs). He consequently feels they should be judged on their "three true outcomes," namely home runs allowed, walks allowed, and strikeouts. This study really confused some of the stat heads for a while. Later on Tom Tippett (and perhaps others) came out with some results to the contrary. I can't make up my mind where I stand on the subject.

As it pertains to my program, it would be easier to use McCracken's philosophy, but I worry that that would be overly simplifying things. If I don't use it though, I feel I will have a lot of sample size issues with my inputs as there is a lot of noise to be dealt with. Any thoughts on the best way to resolve this?

[thelyingthief]

if you're creating a simulation, you certainly don't want to use factors that are wrong, would you?

[mickeyg13]

Well it basically comes down to the following. If you combine both the work of McCracken and Tippet, it seems that pitchers don't have as much control as we thought over whether a ball in play is a hit or not. However, over the course of their careers good pitchers have demonstrated this ability to some extent. The problem is that there is a large variance from year to year, and pitchers that are great in this area one year may be bad the next year. In other words, this ability is hard to measure, and it takes a lot of data to be able to do so. An entire season's worth of batters faced isn't enough to estimate a pitcher's "true" ability to prevent base hits on balls in play. I reluctantly feel I might be forced to assume the league average ability in order for my model to work, but I'd rather not if possible. It seems to take a large portion of a pitcher's career for there to be evidence of an ability to prevent hits on balls in play, so by the time that ability has shown itself, because the pitcher has aged during this time, it might not be the same as it used to be. I'd appreciate any clever insights as to how to estimate a pitcher's true ability to prevent hits on balls in play though.

[kyleb]

DIPS is not pure; there are definitely pitchers that consistently depress their BABIP as compared to league average (Barry Zito, Jamie Moyer). That being said, xFIP is one of the best statistics available to evaluate pitchers' true talent levels.

I suggest running regressions of your own to make your conclusions.