The Billings Mustangs play their home games at Dehler Park. The ballpark opened up in 2008, taking over for Cobb Field which had been in Billings since the 1930’s. The park dimensions are 329 feet to left field, 410 feet to center field and 350 feet to right field.

The Mustangs play in what is considered an incredibly hitter friendly league. There are some ballparks in the league with dimensions that are a joke, including one stadium where it’s 279 feet to the foul pole. Dehler Park has been considered as the most pitcher friendly park in the Pioneer League in the past. This is just a reminder that all of the numbers below are only for a comparison between Billings and other parks in the Pioneer League, not against other parks in all of the Minor Leagues.

How did the 2017 season play out at Dehler Park?

The first thing we are going to look at is how batting average was altered by the field in comparison to the rest of the league in 2017.

dAVG %Change
To LF -.114 -18.9%
To CF -.060 -11.1%
To RF -.066 -12.3%

Given what we know about history of the park in Billings and the rest of the league, these results aren’t surprising. But, when we look at hitters, and try to compare them to the rest of the league, particularly in 2017, we need to realize that their average was severely impacted at home. The results were similar in 2016, with the exception of right field, which saw a difference of 83 points and actually helped hitters to a very small extent.

Of course, it’s usually how power plays in a ballpark that gives a place it the reputation for being pitcher or hitter friendly. Let’s take a look at how Dehler Park played when it comes to power by looking at Isolated Power, which is average subtracted from slugging – essentially just looking at extra-base hits.

dIsoP %Change
To LF -.135 -36.2%
To CF -.089 -44.3%
To RF .038 10.6%

In 2016 the ballpark hurt power to all three parts of the field, but not a ton. In 2017 the ballpark really crushed power to both left field and to center. Surprisingly, it helped power to right field, even while hurting average. The amount that the park suppressed power, even knowing it’s history, was shocking to see. It could just have been random variance, maybe the wind was strange in 2017 – but either way, it was drastic.


The ballpark in Billings continued to be one of the worst parks for hitters, but best parks for pitchers in the Pioneer League in 2017. It held batters back on average and power in a big way by comparison. Overall, Dehler Park probably isn’t as harmful to hitters as the numbers suggest – because the rest of the league is just that hitter friendly, but we do need to try and make some mental adjustments when looking at Mustangs hitters and pitchers numbers if we are trying to compare them to other players in the league.


4 Responses

  1. The Duke

    Is it possible to compare the leagues to each other in regards to park factors? I know having a nearly completely different set of players in each league has to be an issue, as well as being developmentally better as you climb up the ladder. An algorithm that could forcast what a hitter did in Billings and how that might translate to Dayton would be fascinating to me. Similarly for going from Daytona to Pensacola. The rookie ball to Low A and High A to AA jumps are typically considered the biggest for minor leaguers.

    • Doug Gray

      It’s possible because other places do it, but I ‘m not entirely sure of their methodology and how they handle it. You can, of course, try to do it by using players who played in multiple leagues, but you are going to wind up with limited data, particularly jumping from rookie ball to full season ball.

      When it comes to trying to translate numbers, what may be a way to go is simply taking players lines, as a whole, who went from one level to another from one year to the next. The sample size should be good. Obviously that’s not going to work for every kind of player, but you would probably get a general idea that say, going Billings to Dayton will cost a hitter x points of OPS, and so on.

  2. Michael B. Green


    Does this ballpark analysis improve your outlook on Jeter Downs? At that age, with that plate discipline, and the park, it sure looks like he is even better than his numbers.

    • Doug Gray

      It didn’t really. I knew how the park played, though maybe not to this extreme for last season. For a guy like Downs, I had much better scouting reports on him because of the caliber of prospect that he is versus some other guys, where I may rely slightly more on their numbers and the lesser informed scouting reports.