The Effects of Safeco in 2012
So, I’ve been looking into this Safeco Field home/road split thing for the last week or two, and finally got around to writing up some information from a data-centered perspective. While everyone seems to focus on the team’s lack of hitting at home, the reality is that the evidence suggests that there’s just some crazy park effect going on in Seattle this year. It’s not just the Mariners hitters that are struggling in Safeco, it’s everyone, and to almost the same degree.
Anyway, I ended up writing 1,500 words on the subject over at Fangraphs, and you can read the full explanation over there, but the gist of it is that I think the weather is probably the main culprit. Seattle has been abnormally cool this year, especially relative to the rest of the country, and the park is just destroying home runs while turning balls that would be extra base hits into outs. From an observational standpoint, it appears that the marine air has been holding the balls up long enough for outfielders to run under them, and the climate in Seattle this year has turned Safeco into Petco North.
Whether this will continue or not, I have no idea — I’m not a meteorologist and I can’t speak to expected climate changes. It seems like, though, that this isn’t something that will persist, as Safeco’s been open for 13 years now and we’ve never seen it play anything like this before. My guess is that eventually the weather will get warmer and the ball will start to fly a bit.
Until then, though, realize that this is not something that is just affect the Mariners hitters. This is a park effect that is treating everyone equally, and we need to adjust our understanding of player performance accordingly.