The stifling challenge Coors Field presents to Astros pitching

Coors Field is not an ordinary hitters’ park, it’s a pitchers’ graveyard. The Astros are in Denver to do battle with the Colorado Rockies at their notorious home venue. The thin Colorado air enhancing the carry of fly balls is typically what receives the most press, but what might be as equally detrimental for pitchers is the decrease in pitch movement.

In 2020, the Astros played a pair of games at Coors Field and won both, but in shootout fashion, scoring 23 runs combined while allowing 14 combined. Framber Valdez and Cristian Javier were the Astros’ starters for the two-game series, and neither avoided the Mile High City’s patented effect on pitches.

Valdez turned in a fine performance, going 7.2 innings and allowing 3 runs (1 earned). While his final line might not have indicated anything was off with his arsenal, data from Brooks Baseball says otherwise.

According to Brooks, the renowned curveball that the Astros lefty prominently features lost a fairly substantial amount of vertical drop. The fact that Valdez still managed to produce an exceptional start in spite of this hindrance is thoroughly impressive. Javier, on the other hand, was unable to achieve similar success.

After 3.2 innings in which Javier threw 78 pitches and allowed 3 runs (all earned), he was lifted. The three runs came via two home runs. Both were against Javier’s four-seam fastball, which had the least amount of average vertical movement of any outing in 2020 by a decent margin, per Brooks.

Javier doesn’t possess the curveball that Valdez does and seldom throws his anyway, but an important aspect of Javier’s game is the rising four-seamer. Coors Field greatly suppresses the downward movement of a curveball, but does the same inversely to a rising four-seamer.

Following Tuesday’s 6-2 loss, José Urquidy is slated to start for the Astros Wednesday afternoon in Denver, and his pitch arsenal could be affected on multiple fronts. Like Javier, Urquidy’s four-seamer possesses quality vertical movement. Thus far in 2021, it’s been the Mexico native’s most effective offering. It’s missed bats, netted strikeouts and has solid overall batted ball data.

Urquidy relies on his fastball a lot, throwing it 56.3 percent of the time, and continues to display superior command of it from an eye test standpoint. This notion is confirmed by the command metric Shadow% via Baseball Savant.

Another area of concern for the Astros righty is a sub-80s slider, his go-to secondary pitch. It’s been found that the slider is the pitch that’s least affected by the Colorado climate, but Urquidy’s is fairly loopy and is more of a slurve. Although he’s pitched in Colorado before in 2019, Urquidy’s significantly revamped the movement on his repertoire since, so it’s not easy to project how it’ll hold up this time around.

Ahead of his start, the question for Urquidy isn’t how drastically different his overall pitch movement will be, it’s how he’ll adjust his arsenal and all-around pitch usage. His ability to optimize his game in a suppressive environment may ultimately determine the outcome of Wednesday’s contest.