Fantasy Impact: Park Effects

One factor that I try to keep in mind when constructing a fantasy baseball roster is park effects. What impact, if any, does playing home games in a certain ballpark have on a player's statistics, and therefore his fantasy value? To start the discussion, here is a site listing Park Factors for 2009 from ESPN:

http://espn.go.com/mlb/stats/parkfactor

A few surprises here:

AT&T Park is the 10'th best park for scoring runs? Now THAT is a surprise, but not so much so if you were aware that AT&T has played close to neutral for the last several years. This fact makes Aaron Rowand's constant kvetching about how many HR's the park has cost him all the more galling, especially since Rowand's complaining may be scaring off potential free agent hitters.

After all the hoopla about the new Yankee Stadium being a bandbox in a wind tunnel, it turned out to be fairly close to neutral: A bit easier to hit HR's, but overall a bit more difficult to score runs.

There is a significant year-to-year variation. For instance, Mall of America Field in Minneapolis jumped from one of the 3 toughest parks for hitters in 2008 to the 6'th easiest. This makes you wonder about the statistic in the first place.

I think we can agree that the top 3 and at least 2 of the bottom 3 parks here are not big surprises: Coors Field(Colorado), Chase Field(Phoenix), and Wrigley Field(Chicago) are all generally accepted to be friendly to hitters, while Petco Park(San Diego) and Dodger Stadium are well known to be pitcher friendly.


So, how much stock to I put into park effects when constructing a fantasy baseball team? For the most part, I ignore it, except for the parks at the extremes. If a player has established a peformance level in a certain park, like Adrian Gonzalez in San Diego, I don't worry too much about the park. If, however, a player is moving to or away from one of the extreme parks, I pay a lot of attention!

I will not roster any pitcher from the Colorado Rockies without a 2-3 year track record of success there. Of course, no pitcher in history has ever been able to sustain success there, so I don't roster Colorado pitchers! On the other hand, hitters who are acquired by the Rockies from other teams, or hitting prospects coming up from the minors are a fairly good bet to put up better numbers than in their previous home, or from what you would ordinarily project for a hitting prospect.

I stay away from San Diego Padre hitters. The big exception, of course, is AGone, who has established a track record of fantastic numbers in Petco Park. On the other hand, if I am looking to pick up an overlooked starting pitcher who will put up Quality Starts, a few K's and W's and help keep the ERA and WHIP down, I will take a long look at 4'th and 5'th starters in San Diego's rotation even in a 10 team league. Kevin Correia rewarded this strategy for me last year. One pitcher who I expect to be a big beneficiary of park factors is Clayton Richard acquired from the White Sox in the Jake Peavy trade last year. That's not to say I will draft Richard in the early rounds, or even draft him at all, but I will be closely watching him. If he starts getting in a groove of quality starts, and I need a pitcher at the back end of the rotation, I will be quick to pull the trigger on picking him up. BTW, I would stay away from Jake Peavy! Aside from the obvious age and injury issues, he is moving from the most pitcher friendly park and division to one of the more pitcher unfriendly environments. Add at least 0.6 to as much as 1.00 to his ERA!

There are other factors within the larger concept of Park Factors to consider. The Green Monster in Boston is obviously a factor as is the short RF porch in Yankee Stadium(I am cautious about LHP's in Boston and RHP's in New York. For those of us who watch a lot of Giants games, it appears that AT&T park is a lot harder on LH hitters than RH(Barry Bonds was the one big exception).