The MLB is unique among the major sports in that there is a very measurable difference between each team’s home field – the park dimensions (could you imagine if the NFL decided that the field at MetLife Stadium was going to be change to 90 yards next season?). And it makes logical sense that fields with shorter fences are going to be easier to hit home runs in, which over a large sample size would yield more fantasy points for batters.
Here’s another thing about park dimensions, though; they are mostly static. Sure, every now and then a fence is moved in or out, but for the most part a stadium in 2015 is physically the same as it was in 2014. I think there are just so many other variables in play that it sometimes is hard to separate pitching performance, batter performance, DFS site pricing, and everything else that goes into exceeding or falling short of value that the static ballpark differentials become obscured.
At Fantasy Labs, everything is considered in Plus/Minus, projections against price points, Vegas lines, etc. Considering DFS sites raise and lower prices based on recent performance and how pitchers and stadiums are perceived, it wouldn’t make sense for the Plus/Minus values to remain constant, and they don’t. On the left is the top five Plus/Minus ballparks in 2014 and the right shows 2015. Coors is no surprise, but the next tier of parks where players have most frequently exceeded expectations shows little carryover.
Backing up to a team level, each of the teams corresponding to the top parks on the 2015 list are currently in the green in terms of total Plus/Minus, with the Diamondbacks, Reds, and Rockies rated one-two-three. Where do these three teams rate in terms of runs scored overall? Four (Rockies), 21 (Reds), and nine (Diamondbacks).
So price matters, obviously, but how much is pricing influenced by game location? It’s difficult to tell, honestly. There’s a lot going on with this next section, so it’s hard to say there is a definite correlation in all cases (definitely with Coors), but I’m running queries to find out how frequently players are priced above $4000 on DraftKings depending on ballpark. This first one shows when the opposing team it Colorado and the team is the visitor (in other words, Home is hosting the Rockies and Visitor is facing the Rockies at Coors).
No surprise here – players are priced above $4000 much more frequently when visiting Colorado vs. hosting Colorado (I’m focusing on the Count column here). Here is the same thing with the Diamondbacks:
Arizona has played two more home games than away at the time of this writing, but still a pretty big difference. For the Padres, we can see players are generally priced down when playing in San Diego, which also makes sense.
It’s hard to tell to what degree this is a factor in pricing though. For instance, there’s no noticeable discount when players visit Kansas City this year:
Or Miami:
And those are two parks I generally consider “pitcher parks.”
Ballparks are important in MLB DFS, obviously. When you are weighing the ballpark as a factor in your lineup decisions though, make sure you are considering the ballpark itself as opposed to what has taken place at that ballpark.
