Roy Oswalt is quite possibly the greatest Astros pitcher I've seen in my lifetime as an Astros fan. Sure Roger Clemens has a stake to that claim, but it's my subjective opinion and it's my article so Oswalt wins.
I followed Roy Oswalt almost his entire career even in the minors. I remember picking up a preseason magazine and seeing his name as a future impact player for the Astros. He was highlighted mainly because he had helped USA win gold at the 2000 Olympics in Sydney, Australia. Shortly after reading that article he made his debut with the Astros May 6, 2001, and man did he make an impression.
In 28 games, 141.2 innings, 20 of which were starts he won 14 games and lost only three. His 2.73 ERA was pretty good and his 170 ERA+ was even better. He finished fifth in the Cy Young voting, 22nd in MVP and second (to Albert Pujols) in Rookie of the Year voting. He was a force to be reckoned with and he was easily my favorite Astros outside of Craig Biggio and Jeff Bagwell.
Yes Oswalt has been on the decline for a while as a pitcher, but did you know this is the first year he's posted an ERA+ and to be honest he's not pitching all that badly for the Rangers. In fact he's striking out more than eight batters per nine innings for only the fourth time in his career. If anything he's been a little too hittable with with a .379 BABIP and ridiculously high 19% homerun to flyball rate. But this isn't a post about Oswalt's struggles with the Rangers, instead it's about his win total with the Astros, 143.
Those 14 wins in his first season started a streak of eight years with double digit wins. He would win eight in 2009 largely because he was only an average pitchers that year, 100 ERA+. He would go 6-12 with the Astros in 2010 before he was traded, largely because he was a slightly average pitcher. Ahhhhh, so wins don't really correlate all that well with how good a pitcher is. Huh, who would have thunk it.
As you know (or should know if you're an Astros fan) Joe Niekro is the franchise leader in wins among pitchers. Roy Oswalt finished just shy of that mark, but fell shy of that mark by pitching over 300 less innings than Niekro. Maybe Oswalt wasn't the best pitcher in my lifetime, but he was certainly a pretty good one.