During the Championship Era, the Astros have a storied history of improving mediocre pitchers or turning apparent lumps of coal into diamonds. In the latter category, guys like Darryl Kuechel and pretty much every Latino pitcher who was so instrumental in bringing a World Series trophy back to Houston in 2022 come to mind.

In the first category, there’s another long list: Gerrit Cole, Charlie Morton, Chris Devenski (remember when he was an All Star), Will Harris, Collin McHugh, Ryan Pressly. There’s more. Hell, a lot of people thought Justin Verlander’s career was headed for oblivion before he came to Houston and suddenly resurrected, winning two Cy Youngs and throwing a no-hitter after coming to Houston in his late 30s.

When the Astros paid an astronomical sum for the privilege of loaning Yusei Kikuchi and also acquired failed reliever Caleb Ferguson from the Yankees for 2024, it was assumed that the Astros’ “Nerd Cave” and pitching coach Josh Miller had a devilishly genius plan to improve these pitchers, as the Astros’ staff had done for so many before.

At first glance, both look like another miracle. Kikuchi’s ERA with the Astros is 2.89, compared to a season average of 4.39. The Astros have won all five games he has started by a combined eight runs. It’s conceivable that they would have lost most or all of them had the traded Jake Bloss started those games.

And in his last seven appearances, Ferguson has not allowed a single run. It is the longest scoreless inning streak of the year for Ferguson. Yankees fans following this phenomenon are chanting in unison: “WTF.”

I’ve long followed the transformative magic of the Astros’ pitch coaching staff, and when I decided to take a closer look at these two examples, I expected to see a significant improvement in their fundamental performance, as evidenced by advanced peripheral statistics.

I was disappointed.

Don’t get me wrong. These trades were necessary, although in the case of Kikuchi they were apparently overpriced. But it’s too early to say that the Astros team has pulled off another transformational miracle in the case of 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 just 5.4, nearly five below the season average.

He’s been lucky in his last seven games. BABIP: .176 compared to a season average of .310. His home run-fly ball ratio has been unlucky this season: 15.4%, but since joining the Astros he’s been lucky: zero in his last seven, obviously.

If the Astros have done anything to change Ferguson, it’s been the type of contact he allows. His hard hit percentage has dropped from 28.7% to 11.1%, according to Fangraphs. His average EV has dropped from 88.2 MPH to 83.1.

Then there is Kikuchi.

There’s been a lot of talk about how changing his pitch selection has led to his success as an Astro. Maybe. But it also seems like he’s probably just improving by regressing to the mean. And there’s some luck involved, too.

Kikuchi’s FIP, xFIP and SIERA for the season are 3.65, 3.38 and 3.47 respectively, all well below his season ERA, which has only dropped slightly as an Astro (3.60, 3.15, 3.32). His improvement in run allowance was overdue.

His K/9 has improved only slightly, from 10.34 to 11.25. But his BB/9 has also improved by about one per game. Average exit velocity hasn’t changed: 90.7 MPH. One thing that has changed significantly is BABIP: exactly 100 points less at .219.

The Kikuchi trade may have saved the Astros’ season. I’m glad the trade was made. But I’m skeptical of coaching miracles. He had as much luck pitching for the Astros as he had unluck pitching for the Jays in a small sample.

This should be taken into account when the Astros discuss a long-term contract with Kikuchi in the offseason.