HOUSTON, TEXAS - AUGUST 16: Yordan Alvarez #44 of the Houston Astros jogs to the dugout after the sixth inning against the Chicago White Sox at Minute Maid Park on August 16, 2024 in Houston, Texas. (Photo by Tim Warner/Getty Images)
Caleb Ferguson and Yusei Kikuchi: Astros Pitch-Coaching MIracles? Not so Fast.
Small sample size and expected regression may have more to do with the sudden uptick in these two’s results than a miracle of Astros coaching.
During the Championship Era, the Astros have a storied history of improving mediocre pitchers or creating diamonds out of seeming lumps of coal. In the latter category, guys like Darryl Kuechel and just about every Latino pitcher who was so instrumental in bringing a World Series trophy back to Houston in 2022 come to mind.
In the former category, well another long list: Gerrit Cole, Charlie Morton, Chris Devenski, (remember when he was an All Star) Will Harris, Collin McHugh, Ryan Pressly. There are more. Hell, many people thought Justin Verlander’s career was on the fast track to oblivion before he came to Houston and was suddenly rejuvenated, winning two Cy Young’s and throwing a no-hitter after coming to Houston in his late 30’s.
So when the Astros paid an astronomical sum for the privilege of renting Yusei Kikuchi, and also taking a 2024 failed reliever, Caleb Ferguson off the hands of the Yankees, it was assumed the Astros “Nerd Cave” and pitching coach Josh Miller had a diabolically ingenious plan for improving these pitchers like the Astros’ staff had done for so many before.
At first glance they both look like another miracle. Kikuchi’s ERA with the Astros is 2.89, down from a season average of 4.39. The Astros have won all five games he has started by a total margin of eight runs. It is conceivable that with traded-away Jake Bloss starting those games, they could have lost most or all of them.
And in his last seven appearances, Ferguson hasn’t allowed a single run. It’s the longest scoreless inning streak of the year for Ferguson. Yankees fans tracking this phenomenon are exclaiming in unison, “WTF.”
I’ve long tracked the transformative magic of the Astros pitch-coaching staff, and when I decided to take a deeper look at these two examples, I expected to see marked improvement in the underlying performance of these two as indicated from advanced peripheral statistics.
I was disappointed.
Don’t get me wrong. These trades were necessary albeit, in the case of Kikuchi, seemingly overpriced. But it’s too soon to say that the Astros staff has worked another transformative miracle in the case of either Ferguson or Kikuchi.
Let’s start with Ferguson.
During his scoreless streak, Ferguson’s FIP is 4.22 compared to a season average of 4.32. His xFIP and SIERA are actually much worse: xFIP 5.58 compared to 3.87, SIERRA 6.22 compared to 3.73. His K/9 is only 5.4, down almost five from season average.
He has been lucky in these last seven games. BABIP, .176 compared to a season average of .310. His home run to flyball rate has been unlucky for the season: 15.4% but lucky since joining the Astros: zero in the last seven, obviously.
If the Astros have done anything to alter Ferguson it has been in the nature of the contact he allows. His hard hit% has declined from 28.7% to 11.1% per Fangraphs. His average EV has declined from 88.2 MPH to 83.1.
Then there’s Kikuchi.
Much has been made about how the change in his pitch selection has led to his success as an Astro. Maybe. But it also looks a lot like he was likely to improve merely from regression to the mean. And there’s some luck, too.
Kikuchi’s FIP, xFIP, and SIERA for the season are 3.65, 3.38, and 3.47 respectively, all far below his season ERA. These have dropped only slightly as an Astro (3.60, 3.15, 3.32). He was overdue improvement in run allowance.
His K/9 has improved only slightly to 11.25 from 10.34. But his BB/9 has also increased about one per game. Average exit velocity has not changed: 90.7 MPH. One thing has changed significantly, BABIP: exactly 100 points less at .219.
The Kikuchi trade may have saved the Astros season. I’m glad for the trade. But I’m dubious about any coaching miracle. He’s been as lucky pitching for the Astros in a small sample as he was unlucky pitching for the Jays.
This ought to be taken into consideration when the Astro talk long-term contract with Kikuchi in the off season.
