In the midst of all the conversation about Brandon Moss' move to Cleveland, one thing that has come up a number of times (I've brought it up myself) is that Moss is moving from one of the worst power parks for lefties to hit home runs to one of the best parks for lefties to hit home runs.
According to FanGraphs, O.co Coliseum, home of the A's, has a park factor of 88 for HR by left-handed hitters; Progressive Field had a factor of 109. That basically means that playing games in Oakland depressed Moss's HR by 12% while playing in Cleveland should increase them by 9%, as compared to a neutral park.
That is a pretty extreme difference. A left-handed power hitter like Moss couldn't find a worse home park in the American League than Oakland. That 88 park factor is the lowest in the AL and third lowest in baseball (San Francisco and Miami are lower). That 109 in Cleveland? That is tied for third highest in the AL and sixth highest in MLB.
So what can we expect from Moss in his new, much more friendly home park?
Well, Moss hit 25 HR last year with the A's. He hit 30 the year before and 21 in 2012, so that 25 from 2014 is also basically his three year average.
Let's assume that his true talent is a 25 HR season in Oakland. Moving him from Oakland to a neutral park, his 25 HR would turn into 28.4 bombs. Shifting those 28.4 neutral park home runs would take us up to 31 HR in Cleveland. 31!
That is six extra HR thanks to a change in scenery. Not too bad. But there is more to it than that. HR typically come on fly balls and fly balls that don't turn into HR almost always turn into outs. BABIP on fly balls is around .125, meaning that roughly one in eight non-HR fly balls turns into a hit. So of the six HR Moss would have hit in Cleveland, but didn't in Oakland, almost all of them turned into outs instead.
Of course, those six fly balls would all have been hit hard and deep, so let's assume his BABIP was higher than normal and that two of the six banged off the wall and turned into doubles, instead of becoming outs.
Last year, Moss posted a ..234/.334/.438 line in 500 AB and 580 PA. But what we found above is that four of his outs and two of his doubles would have turned into HR. This adds four more hits and times on base, and 20 more total bases. Add those in and his line looks like this: .242/.341/.478.
That is no joke.That is a significant impact on his slash stats, taking him from a .772 OPS to .819. That first number is barely higher than Denard Span (or Lonnie Chisenhall), while the second number is ahead of Hanley Ramirez or Adrian Gonzalez, and everyone on the Indians except for Michael Brantley.
Of course, that is what he would have done the last three years, not what he will do next year. He's also a year older and coming off a hip injury. But the player the Indians acquired for Joey Wendle would have put up a top-30 OPS in all of baseball last year had he played his home games at Progressive Field instead of O.co Coliseum.