5 Greatest Houston Astros Pitchers of All Time

While Oswalt's 38 team WAR leads all Astros pitchers, the only thing missing from an already quite-full mantle is a Cy Young award, despite finishing top-five in voting on five separate occasions.

Oswalt was the ace of the Astros staff that won the National League pennant in 2005, and won NLCS MVP with his 1.29 ERA in two starts, including seven one-run innings in Houston's decisive Game 6 win over the Cardinals. While the Astros would be swept by the White Sox in 2005, it was Oswalt who got them there, and he was quietly one of the best pitchers of that franchise era.

His career 3.28 ERA with the team is more than respectable, and his 143-82 record and 136 ERA+ while with the Astros is a testament to his reliability on the mound.

To get there was no easy feat either, as "The Wizard of Os" was a 23rd-round pick in 1996.

3. Roger Clemens (2004-2006)

Clemens' time in Houston was brief, but represents arguably the greatest peak of any Astros pitcher in history.

Thought by many to be retiring after the 2003 season with the Yankees, Clemens couldn't stay away from the game of baseball, signing a one-year deal with his adopted hometown team and joining longtime Yankees teammate Andy Pettite.

At the age of 42, Clemens won the Cy Young, finishing the 2004 season with an 18-4 record and 2.98 ERA, which was the highest of his three seasons in Houston. He started the All-Star game that year, and was strong until the sixth inning of Game 7 of the 2004 NLCS against the Cardinals.

Fueled by his excellent 2004 campaign, Clemens stayed on the diamond and signed a one-year, $18 million contract that was a record for annual value given to a pitcher.

"The Rocket" delivered on his value, leading the majors with a 1.87 ERA, a mark that was not only the lowest of his 22-year career but also the lowest by any pitcher since Greg Maddux in 1995.

Before Jacob deGrom or Paul Skenes, there was Clemens in 2005, as the All-Star ace only went 13-8 due to abysmal run support from an Astros offense averaging just 3.5 runs per game.

Still, Clemens reached several major milestones while in Houston, including hitting 4,500 strikeouts and finishing behind Ryan in the all-time strikeouts list just 20 years after Ryan eclipsed 4,000.

2. Justin Verlander (2017-2024)

The Astros made a shrewd trade for Verlander on August 31, 2017, more than a month after the trade deadline but just before the September 1st deadline for playoff eligibility. The team dealt three prospects for the soon-to-be ace of the staff, including catcher Jake Rogers and flashy outfielder Daz Cameron, but none panned out for Detroit much like JV for the Astros.

Verlander proved to be the missing piece needed for the franchise to summit the mountain, and not only turned around the 2017 season, but the entire history of the franchise. Verlander went 5-0 with a 1.06 ERA in the month of September, and dominated the 2017 postseason, earning ALCS MVP honors after pitching to a 0.57 ERA and throwing a 124-pitch complete game against the Yankees in Game 2.

Verlander stepped up his game big-time in 2019, going toe-to-toe with fellow ace Gerrit Cole, then eight years his junior, and produced his first 300-strikeout season en route to his second Cy Young award.

His 2022 season, though, was his greatest comeback story, as he had missed two seasons due to Tommy John surgery yet came back with a 1.75 ERA to win his third Cy at the age of 39. He stands among the best pitchers in Astros history due to his combination of championships, longevity, and dominance at his peak.

1. Nolan Ryan (1980-1988)

While Ryan can be argued to be the best pitcher of all time, the bulk of his legacy was crafted with the California Angels, where he pitched four of his record seven no-hitters and set the all-time strikeout record (383 in 1973).

That said, the entire back end of Ryan's career was spent in his home state of Texas, and the more successful years in Houston rather than Arlington.

Ryan is moreso the most iconic pitcher in franchise history, as "The Ryan Express" produced a ridiculous 33 WAR while with the team, justifying his 1979 contract with the Astros (four years, $4.5 million) that made him the first MLB player to earn $1 million per year.

While Ryan was vital to the Astros' 1980 division championship and pitched in the 1986 NLCS, he does lack the same team playoff experience as his contemporaries on this list.

Ryan donned an Astros jersey when he became the first pitcher in MLB history to reach 4,000 strikeouts on July 11, 1985. Across nine seasons, the ace struck out 1,866 batters in 282 starts.

Ryan's No. 34 was retired by the Astros (also fittingly the case with the Rangers and Angels) and he was inducted as a foundational member into the Astros Hall of Fame.