Toolshed: Assessing Triple-A park factors
Not all offensive jumps are created equal. As has been widely documented, there was an offensive explosion in Triple-A this season with Pacific Coast League clubs averaging 5.9 runs per game and their International League counterparts averaging 5.2, up from 5.0 and 4.2, respectively, in 2018. A primary driver of
Not all offensive jumps are created equal.
As has been widely documented, there was an offensive explosion in Triple-A this season with Pacific Coast League clubs averaging 5.9 runs per game and their International League counterparts averaging 5.2, up from 5.0 and 4.2, respectively, in 2018. A primary driver of this offensive uptick was the switch to the Major League baseball. But while every Triple-A player utilized the same ball, they weren't playing in the same environments. Some were in extreme hitters' parks, even by Triple-A standards, while others were working mostly in friendlier confines for pitchers.
Toolshed last reviewed Triple-A park factors in 2016, so it's high time to return to the subject, especially after a year of movement in the PCL. Notably, Triple-A's western circuit dropped Colorado Springs, replacing it with San Antonio. In addition, a new ballpark opened in Las Vegas, meaning the 51s/Aviators replaced a hitters' park (Cashman Field) with an even more extreme hitters' park (Las Vegas Ballpark).
The following are the park factors for the Pacific Coast League, first for the 2019 season and then an average over the past three seasons. In the second table, Las Vegas is split into two groups to illustrate the difference between the two stadiums, while Colorado Springs and San Antonio are included separately. The scales for the run, home run and hit factors are constructed so 100 equals average -- anything above favored hitters while anything below was more helpful to pitchers.
Pacific Coast League -- 2019
Pacific Coast League -- 2017-19
|Colorado Springs '17/18||133||115||108|
|Las Vegas '19||124||153||122|
|Las Vegas '17/18||113||115||109|
|San Antonio '19||89||82||98|
The first thing that stands out is how the two stadium changes impacted the PCL landscape. The league traded one of its most homer-happy parks, located in the high altitude of Colorado Springs, for something more down to Earth in San Antonio. As a result, the collective ERA of Brewers Triple-A hurlers went down from 4.60 at Colorado Springs in 2018 to a league-best 4.15 this season with San Antonio.
Las Vegas became even more hitter-friendly in its new home, something that may have not seemed possible given how balls used to fly out of Cashman Field. As a team, the Aviators posted a .531 slugging percentage and a .902 OPS this season -- the highest single-season marks for an individual club since at least 2005. A big reason for that may be the new ball, but another explanation is certainly the new stadium. To further the point, Las Vegas pitchers gave up a league-high 145 homers at home this season, compared to only 79 on the road. According to BaseballParks.com, the elevation at Cashman was 1,995 feet; while at Las Vegas Ballpark, it's 3,041 feet. A climb to a higher locale while staying in the dry desert air is a good way to get a jump in offense.
Lastly, El Paso made headlines for setting a modern PCL record with 258 home runs as a team, eight more than Vegas. But the slightly above-average 106 home-run park factor indicates the Chihuahuas didn't receive as big a boost from Southwest University Park as one might imagine. In fact, El Paso sluggers actually hit more homers on the road (130) than they did at home (128) over equal 70-game samples in 2019.
Now onto the other Triple-A circuit...
International League -- 2019
International League -- 2017-2019
Charlotte, Charlotte, Charlotte.
There's no way to talk about park factors and the IL without addressing the elephant in the league: BB&T Ballpark. The Knights opened the stadium in 2014, and offense has taken off in downtown Charlotte ever since. In 2019 alone, Knights batters belted 127 homers in their friendly confines, compared to only 81 on the road. Pitchers had it even more extreme. Charlotte hurlers gave up 130 dingers at home, as opposed to nearly half that at 73 away. Only Albuquerque pitchers (133) allowed more long balls at home in 2019. Basically, the Knights enjoy -- well, their level of enjoyment might vary by position -- playing in a PCL park at home and taking on fairer IL parks everywhere else in their own league.
In other spots, the IL might stand out more for pitching advantages than those given to the hitters, even in a big offensive season like 2019. Toledo batters hit 100 homers on the road but only 55 at home this past season -- the biggest home-to-road drop for an offensive unit this season. Elsewhere, Norfolk has been the more pitcher-friendly park in recent years. Tides batters went yard 145 times at home over the past three seasons, compared to 84 more (229 total) on the road over that same span. Norfolk pitchers, meanwhile, have fared better, giving up 189 dingers at home in those three seasons, a drop of 30 from the road total of 219.
Coming Toledo attractions: Much has been said about the Tigers' deep arsenal of arms at the Double-A level in 2019, led Top-100 prospects Casey Mize, Matt Manning and Tarik Skubal. What happens when all three, as well as Alex Faedo and Joey Wentz, head to Triple-A Toledo next summer? Likely good things, at least in terms of numbers. While Detroit's prospect arms adjust to life with the Major League/Triple-A ball, they can relax knowing Toledo's Fifth Third Field conceded 17 percent fewer runs and 26 percent fewer homers than the average IL park in 2019. That should be particularly useful to Mize and Skubal, who give up their fair share of fly balls compared to those on the ground.
Sam Dykstra is a reporter for MiLB.com. Follow and interact with him on Twitter, @SamDykstraMiLB.