Credit the Astros Pitching For Digging Out of a Big Hole after the First Month and a Half
As the Astros slowly try to overcome their disastrous start to the season, creeping closer to a .500 record, the improvement in the pitching performance is perhaps the most important factor. The improved pitching over the past month and a half is even more remarkable when you consider the way that injuries have ravaged the staff. So, let’s see how the Astros’ pitchers performed in March-April compared to May 1 – today (June 23).
- At the end of April, the Astros ERA was in the MLB bottom five at 5.01. Since May 1, the Astros ERA is 9th in the majors at 3.61. The improvement in the bullpen’s ranking is most notable. The Astros’ bullpen ERA of 2.98 is 4th best in the majors since May 1, a reversal from the No. 25 ranking (4.91) at the end of April.
- The Astros also have shown improvement in advanced pitching measures too. The team SIERA was 4.25 at the end of April (5th worst in the majors), but improved to 3.98 after May 1.
- The Astros pitching encountered a very poor BABIP to start the season (ranked 27th worst at .312) and benefited from BABIP regression since then (ranked 6th best after May 1 at .266). At the same time, the pitching staff allowed relatively low exit velocity in both time periods (ranked 7th lowest at 88.4 on April 30 and ranked 11th lowest at 88.8 since May 1). Given the stable EV allowed, the changes in BABIP are probably driven by randomness and improved defense.
- One of the negative stories to begin the season was the bullpen’s tendency to melt down at the worst times. Those late inning crashes leave a lasting impression. But now the bullpen’s tendency to avoid late inning melt downs is a big factor in improving the team win percent. By the end of April, the Astros bullpen experienced 18 melt downs (10th worst in the majors). Since May 1, the Astros bullpen has been the 2d best at avoiding melt downs, with only 12 meltdowns over seven and a half weeks. Only the Dodgers have experienced fewer melt downs during that time period.
- The physical characteristics of the staff’s pitches never have been terrible on a team basis, which was a reluctantly optimistic aspect of performance in March/April. But the pitching staff’s stuff, as measured by Stuff+, decidedly moved upward in the period after May 1. The Astros’ Stuff+ ranking was 12th (101) at the end of April. However, since May 1 the Astros’ Stuff+ ranking is tied with Seattle for 2d best in the majors (106).
- Spencer Arrighetti and Josh Hader have exhibited the largest improvement in Stuff+ between Mar./April and After May 1. Arrighetti’s Stuff+ has improved 27 points and Hader’s Stuff+ has improved 14 points. Arrighetti started pitching at the ML level with a team worst stuff rating, but gradually has improved close to 100 in the recent period. Hader had a good Stuff+ rating of 115 in the early season, but now holds the staff’s top Stuff+ (129) after May 1. Hader has credited his slider for recent improvement, and the Stuff+ rating verifies that his slider has improved by 8 points since May 1.
- Justin Verlander’s return to the rotation will be important. Verlander’s Stuff+ rating of 119 for the recent period is impressive not just for a 40 year old pitcher—but for any pitcher. His stuff ranks closely behind the late inning relievers (Hader, Abreu, and Pressly). Hopefully, he will be able to recover and leave the injured list, because the Astros are unlikely to find another starting pitcher to replace his combination of experience and stuff.
Will the Astros’ pitching staff maintain its recent improved performance? That is an open question. But it will be important if the Astros want to stay in contention for the playoffs.
PLAYOFF ODDS
I like to provide periodic updates to the Astros’ playoff odds. The Astros’ Playoff Odds have moved up to 44%, according to Fangraphs. Baseball Prospectus’ PECOTA odds have been more favorable to the Astros all season. PECOTA’s playoff odds for the Astros now stand at 57%.