In the wake of Victor Martinez‘s season ending knee injury, the Detroit Tigers have swiped up the last remaining big time player on free agency, Prince Fielder.
You may recall that Prince’s daddy, Cecil, was a Tigers star, hitting 51 homers back in 1990. All told he spent six-plus seasons as a low average, high power first baseman and designated hitter, driving in 100 runs four times with Detroit (and it would have been five had he not spent the end of 1996 with the Yankees).
But this article isn’t about Cecil. He’s irrelevant from a fantasy perspective. We care about how this signing affects Prince. In a word, yikes.
One of the first things I do whenever a player switches teams is look at how his old home park and new home park compare. The easiest way to do this is to look at park factors over at Statcorner.com. Miller Park in Milwaukee has a park factor for home runs of 118/103 for LHB/RHB. His new home, Comerica Park, lists as 88/108. The image below shows the dimensions of both ballparks next to each other.
OK, there’s a pretty big difference between 118 and 88, but those are just numbers. How many home runs does that equate to? Using ball-in-play data from Katron.org, we can get a much better answer to that question. For any prospective Fielder owners, you might want to sit down.
The image above shows all of Fielder’s fly outs (orange), doubles (light blue) and homers (dark blue) last season at Miller Park projected on Comerica Park. These numbers are just shocking. Fielder would have lost a whopping 16 home runs at Miller Park and didn’t add any.
Now, that -16 difference was extreme even in the context of the last few seasons. This chart below shows how many homers Fielder would have gained and lost each of the last four years if he had been playing at Comerica Park (four years is as far back as the data goes) as well as what his home run total would have been that year. Obviously this is a rough approximation because the parks Fielder hits at on the road would have been different (and who’s to say his approach would have been the same), but it shows the kind of effect this park change might have had.
Could we really have seen Fielder hit fewer than 30 homers in each of the last two seasons? Last year Fielder lost so many homers because he hit a lot to left-center, and the wall in left-center at Comerica juts out to a 420-foot center field instead of leisurely curving inward before bulging out to just 400 feet. Fielder has tremendous power, but the balls he absolutely crushes are to right field. He doesn’t lose many of these blasts. It’s the ones to left-center and dead center than will begin falling short.
Now, what’s really nice about Fielder is that, unlike Ryan Howard, he hits for a good average. In two of the last three seasons he even topped .290. What happens to all of these would-be homers that are going to fall short? Approximately one in every eight fly balls results in a hit (league average on flies is .125), so it stands to reason that we’ll see a good number more fly outs.
Last year, Fielder batted .299. If 14 of those 16 homers end up being fly outs, that means Fielder loses 14 hits off his season total (170) and his average drops from .299 to .274. Of course, this says nothing of any wall balls that will result from well-hit flies falling a bit short, so that .274 is probably on the low side, but it shows the kind of problems Fielder should experience.
So for anyone looking to spend a first round pick on Fielder, or even a high second round pick, at least know what you’re getting yourself into. Instead of being a 35-40 homer threat with a .290 average, Fielder now appears to be a 30-35 homer player with a .280 average. Gamble if you want, but I’m staying away.




The “overlay” of Comerica vs. Miller is quite compelling, but it I believe it fails to take one factor into account, and that is the natural advantage Comerica has against all hitters, namely visiting hitters. If it’s true that Fielder’s performance suffers (sans any adjustments to his hitting approach in order to compensate) than it’s also true that the HR output of all opponent hitters whose home field walls are shorter is likewise reduced, so on a run for run basis as derived from swinging for the fences, it approaches a zero sum prop, i.e. he’s still hitting as many HRs in Detroit as anyone else. Right? Yes, the question remains “does it make sense for a team with a home field with some longer walls to invest top dollar in ANY slugger vs. someone who hits for primarily for average?” Detroit players (Ordonez and M. Cabrera) have claimed two recent batting titles with excellent averages (.363 and .344) and without blow-out HR totals (28 and 30). The non-tangible, qualitative factor(s) of Fielder being able to make small but contributive adjustments to his batting style may make the whole conversation moot; Comerica’s short right field fence is ripe for any dead-pull LH slugger, but that’s not to say that would be a good goal for Fielder overall. It might be more important for him simply to be able to consistently put the ball in play, with the likes of D. Young, Avila, and Peralta (all potential .300 or better hitters) batting behind him, get the dingers and other hits he gets, and watch him hammer for the fences primarily on the road.
Thanks for the well-articulated comment. You are correct that everyone who visits Comerica will see their hr production fall, but the argument here is Fielder loses fantasy value due to the likely drop in hr totals.
Right. I launched into my spiel not realizing this was a fantasy sight. Sorry.