Well before Tom Tango rose to the level of Senior Database Architect for MLB Advanced Media, he established his own site in which he explores baseball's critical measurements. One recent example involves Wins Above Replacement. Tango has recently come up with CoreWAR and has two simple formulas to calculate a pitcher or non-pitcher’s WAR.
While reading the breakdown of how Tango came to these formulas, I’m drawn to park factors. Whenever I use a metric, whether WAR or wRC+/OPS+, I assume the ballpark tweaks the final result. We all know that pitching at Coors Field is much different than doing so at whatever Oakland Coliseum is called now.
Tango wrote about Coors Field’s park factor, leading me down the rabbit hole at Baseball Savant. Tango and his team have built a page where anyone can look up a stadium’s park factors on various metrics. It's a convenient resource to compare and contrast how each stadium’s environment has played over the years with data tracking back to the 1999 season. Using a three-year rolling average, it’s no shocker that Coors Field is still the most hitter-friendly ballpark. It’s also no surprise that Oakland and San Francisco are the most pitcher-friendly.
Right smack-dab in the middle is Guaranteed Rate Field.
The perception is that Guaranteed Rate Field is a hitter’s paradise, but it's mainly true in just one regard: home run park factors. Coors Field, surprisingly, ranks fifth in Home Run Park Factor. The most home run-friendly ballpark is in Cincinnati at Great American Ballpark. They are followed by Camden Yards in Baltimore, which gives them the American League crown. Perhaps it’s a reason why the Orioles have decided to push back the fences in left field.
Dodger Stadium follows Camden Yards in third place, followed by Guaranteed Rate Field in fourth. As Jim hinted about in Tuesday's Spare Parts, suppose the Orioles get their desired effect of reducing home runs hit. In that case, the White Sox could very well take the crown in 2022 as having the American League’s most friendly home run park.
Since the 2000 season, there have been 4,450 home runs hit at Comiskey Field/U.S. Cellular/Guaranteed Rate Field in 132,110 plate appearances, or 3.36 HR per 100 PA. In 2021, that rate was 3.65 HR per 100 PA.
Here is where my confusion lies: How can a ballpark that is most home run friendly in the American League have a neutral factor for hitters and pitchers? Wouldn’t this launchpad be a haven for run producers and a nightmare for pitchers?
Break down the other batted ball results, and Guaranteed Rate Field behaves much differently. Out of 29 stadiums (Texas is playing in a new stadium and doesn’t count as of this writing), you’ll need to look towards the bottom to find Guaranteed Rate Field.
Park Factors (2019 - 2021)
- Singles: 94 park factor, 28th in MLB
- Doubles: 83 park factor, 29th in MLB
- Triples: 49 park factor, 27th in MLB
While I thought this was a revelation, it isn’t. Looking at the past 21 seasons, Guaranteed Rate Field only tilted to the hitter’s advantage for doubles three times (2004, 2010, and 2012), singles just five times (2002, 2004, 2007, 2012, and 2018), and triples just once (2000). That’s how one of the most homer-friendly ballparks in major league baseball is a neutral environment.
Compared to Coors Field:
- Singles: 116 park factor, 1st in MLB
- Doubles: 120 park factor, 3rd in MLB
- Triples: 220 park factor, 2nd in MLB
Knowing how the home ballpark has been played for two decades makes me wonder if this data should greatly influence the White Sox roster-building. It makes sense that the White Sox have been focused on finding groundball specialists out of the bullpen like recent signee Kendall Graveman. Suppose a pitcher like Graveman can limit the number of fly balls hit. In that case, theoretically, he should find success pitching at home. The ballpark advantage is on his side.
Vice versa looking at the White Sox lineup, if there were one batter to clone, it would be Yasmani Grandal. While Guaranteed Rate Field is not an advantage for a non-home run batted ball results, it’s one of the most friendly to draw walks in ranking third in MLB. Grandal hit 14 home runs at Guaranteed Rate Field in 2021, which accounted for 40% of his total hits at the ballpark. It’s a player/ballpark match made in baseball heaven.
Coming up for air after climbing down the rabbit hole, my perception of the White Sox home environment has changed. Once, I thought it was a hitters haven; now I see Guaranteed Rate Field as a weird place to hit. Great for home runs, but not much else. Truly one of a kind.
