Between the juiced balls and the thin air, Coors Field is back to playing to football scores. The humidor appears to have been neutralized and balls are back to flying out. While it has always been a breeding ground for scoring, Coors Field has elevated to a new level.
After watching nearly a full series at Coors Field, when the Cincinnati Reds traveled there earlier in the month. Two of the three games fit this reputation and were absurd in the scoring totals. However, the series opener was a pitching duel between the Grays…Jon and Sonny.
With this being one of only two games in June and July where both teams scored three runs or less, it had me wondering, what the deal was between the two that had them neutralizing the Coors monster.
When it comes to MLB Park Factors, Coors Field obliterates the competition when it comes to hits and runs and come in a close second to the Rogers Centre in home runs. Park Factors is a measure by ESPN that determines how favorable a park is to hitters or pitchers. Over 1.000 favors the hitters and under 1.000 favors the pitchers. Coors is at a 1.654 in 2019 through Friday night. The next closest hitter-friendly park is PNC Park at 1.174.
However, when looking at the two hurlers, the fascinating aspect of Jon Gray is that he is a better pitcher at Coors Field than he is on the road. Gray’s home ERA in 53 games is 4.51 and his road ERA in 57 games is 4.58. The spread is even more dramatic when looking at 2019. In 10 home games this season, Gray has a 3.90 ERA, as opposed to a 4.29 ERA in 11 games on the road. His H/9 is basically identical and he has allowed three fewer home runs at home.
Sonny Gray has been strong all year for the Reds, but so had Tanner Roark, who allowed 13 hits and seven runs the next day in 4.2 innings of work against a very similar lineup. Now to ask, what stands out about his game?
Sonny Gray has a remarkable spin rate on his slider in 2019. However, Jon Gray does not. Both get tremendous vertical movement though. With the high spin rate, Sonny Gray gets outstanding horizontal movement as well, but the pitch plays great for both. Both pitchers all throw a lot of sliders and curveballs. Sonny Gray throws one of the two pitches over half of the time. Jon Gray isn’t quite as high, but he sees similar results, with opposing hitters batting .175 against the slider and .167 against the curve in June of 2019. Over the same span, Sonny Gray is allowing the league to hit just .100 against his slider and .063 against his curve.
In the game, Sonny Gray through 40 curveballs, and his next closest pitch count was 28 sinkers. According to a FanGraphs report earlier in the year, the curveball is one of the pitches most impacted by the elevation at Coors Field. However, it did not have the same negative impact on his offerings. Gray’s vertical movement on the pitch in the contest was -5.33. That is well under his average for the season, where his worst month was -6.52. However, that is closer than the average difference at Coors Field. According to the FanGraphs report, the average difference at Coors is 2.32 inches difference in vertical movement. In 2019, Gray has the sixth best spin rate in baseball on the pitch.
In the FanGraphs report, they discovered that the slider was the pitch that was least impacted by the thin air. Gray also was quoted in the story, saying that his slider might even be better at Coors. Basically, the key for these two pitchers are determining a pitch that is impacted the least by the environment.
In comparison, Rich Hill has not fared as well as Sonny Gray did at Coors Field. However, his numbers are not as poor as at a lot of locales. Last season, Hill pitched at Coors Field twice, which were his only two appearances there since resurrecting his career with the Dodgers. In the two games, he worked 11 innings and allowed six earned runs. The first game was a six inning gem, where he allowed just a pair of earned runs. The second start was deceiving, as the line said he allowed four earned. However, the first was on a solo leadoff homer by Charlie Blackmon and the second was on a RBI groundout after a triple. He allowed back-to-back doubles in the sixth before the bullpen allowed his last run on a homer. Those four knocks were the only ones that Hill allowed, while striking out seven. Additionally, the vertical movement on his curve in the final game at Coors was -5.16, while his average break was -7.86. Hill was also still able to generate a ton of horizontal break as well, but the splits were about the same from sea level and well above. Though this was much further difference than Gray’s discrepancy, it shows that Hill created so much movement that he was able to still be successful at the elevation.
With this in mind, a high spin rate on a breaking ball and maintaining a lot of both vertical and horizontal break could be the code to help solve Coors Field’s video game play. The issue is that this is much more easily said than done.