He was having a rough season when the Astros traded for him, but Will Smith is proving his worth on his new team.

The Houston Astros’ acquisition of Will Smith at the trade deadline was somewhat confusing. Sure, the team needed a left-handed reliever, but he probably wasn’t the first name that fans had in mind. The Astros have had a reputation as an organization that can get the absolute maximum out of any pitcher for years now. Still, it’s fair if the trade for Smith was met with skepticism, even though it sent Jake Odorizzi the other way and solved their dilemma of having too many starting pitchers.

When he was traded to Houston, Smith hadn’t been trusted to pitch in a week, he had an ERA of 4.38, and was coming off an especially rocky month of July. He did not look like the dominant closer that repeatedly took the life out of the Astros’ offense in the 2021 World Series, and it got worse almost immediately. He gave up a home run in his very first inning with his new team, and after another tough outing against the White Sox in mid-August, his season ERA ballooned up to 4.53, which teeters on being unserviceable as a big-league reliever.

Since then, the Will Smith of old has resurfaced in dramatic fashion, and it couldn’t be happening at a better time for the Astros. A day after his poor performance in Chicago, he tossed a scoreless inning in his former home ballpark in Atlanta, which appears to have been the turning point. He has allowed just earned 1 run in his past 13 outings, establishing himself as a key component of the team’s excellent September in which they have pulled even further away from their competition and clinched another AL West title.

What’s behind Will Smith’s turnaround with the Houston Astros?

What changed? How did Will Smith turn his season around, and what is working in Houston in 2022 that was not working in Atlanta?

So far in September, Smith has a 1.23 ERA in 8 appearances with 8 strikeouts, 2 walks allowed, and 3 hits allowed. The 33-year-old veteran has an average exit velocity of 83 MPH and his hard hit rate is under 30% this month: everything is going right. This is the same pitcher that, when he was acquired by the Astros, couldn’t seem to find the strike zone, and when he did, he was often taken yard.

What’s surprising, though, is that his underlying metrics haven’t really changed too much compared to the rest of the season. There have been no dramatic increases in his spin rate or whiff rate (that has actually decreased), nor has there been a significant mechanical change in the form of an increase in break, a change in release point, or a change in pitch usage. It’s obvious that he has gotten better of late, but identifying exactly what has improved from earlier in the season isn’t as easy because when the Astros acquired him, he wasn’t having a bad season: he was just coming off an atrocious single month.

I mentioned his month of July, a month that saw him post an ugly 9.00 ERA and get shipped out of Atlanta with a season ERA over 4. His season ERA to start the month, though, was 3.30. Looking at his monthly splits, every single one of his underlying indicators has ranged from decent to great in every month of the season except for July. In that month, his walk rate was up, his barrel rate was up, and his xwOBA was near .400. Every other month, it has been .304 or lower.

Wiping his July performance off the record entirely isn’t the way to evaluate Will Smith, but it does provide an interesting thought exercise: his ERA on the season minus July is 2.99. He was having a decent enough season by all means until that final month, which clearly caused the Braves to worry.

As well, looking at the difference between his expected numbers and results shows that he wasn’t as bad as he looked for the first couple of weeks of his Astros tenure: his August wOBA was 50 points higher than his xwOBA. It was in August that Smith posted his lowest walk rates and his highest chase rates of the year.

Here is where hindsight becomes 20/20. The Astros did not acquire Will Smith just for the sake of having a lefty in the bullpen. They didn’t acquire him to transform him and inject him with the fountain of youth, because he didn’t need any of that. He was still a good reliever having a good season when they traded for him who happened to be coming off of one awful month that made his overall numbers look bad enough to worry fans.

It’s not like the Astros’ front office could have guaranteed that he would turn out like this, but it’s now evident what their thought process was in acquiring him. It was also a brilliant job of “buying low” seeing as Smith took a turn for the worst right as the trade deadline approached. There have been plenty of moves made by the Astros in recent years that warrant analysis the size of a small novel, but this isn’t one of them. Will Smith is a good pitcher who happened to be in a short but very magnified slump. The Astros banked on his strengths, and it’s paying off in a big way.