|Oswalt was one of the National League's top pitchers for a decade (LATimes)|
In fact, their careers followed almost identical trajectories and overlapped very well. They were both exceptional during their time together in Houston, which ended two days apart in 2010. Oswalt was traded to Philadelphia on July 29th, and two days later Berkman was sent packing to the Yankees as the Astros began their teardown (the following summer, Hunter Pence would join Oswalt in Philly and Michael Bourn was dealt to the Braves). Oswalt and Berkman were both great for about a decade, then crapped out in their early 30s and finished their careers with around 50 bWAR.
Oswalt's career was relatively short, lasting just 13 seasons. But during those 13 seasons, he was the third most valuable pitcher in baseball behind only Roy Halladay (a one-time teammate of Oswalt's who also happened to be his most similar pitcher at ages 31, 32, and 33) and CC Sabathia, both of whom are likely Hall of Famers.
Oswalt probably won't be, because his career was too short to make up for never winning a Cy Young award or having a killer peak like Sandy Koufax or Pedro Martinez. But Oswalt was very good, better than most people realize. He was good enough to finish in the top six of the Cy Young voting six times from 2001-2010, when he was also durable enough to exceed 200 innings seven times and average 202 per season.
He didn't dominate hitters with overpowering velocity the way Justin Verlander and Clayton Kershaw do today, but instead had great command of his four pitches, consistently finishing among the league's top ten in BB/9 rate and K/BB ratio. That control helped him win an ERA title in 2006 and have a career ERA that was 27 percent better than average.
The three-time All-Star drew MVP votes on four separate occasions. He also won 20 games twice and more than 61 percent of his decisions (for people who care about such things). Oswalt was good enough long enough to be worth 50 wins above replacement level in his career. He was one of the 100 best starting pitchers of all time according to JAWs and bWAR (the latter of which rated him as the league's most valuable pitcher in 2007).
He was also, according to Bill James, the best Big Game pitcher of all-time. Better than Bob Gibson, Whitey Ford, and yes, Jack Morris. That sounds like a ridiculous claim to make of a man who get shelled in his only World Series start, but it's true. His teams went 46-12 in the most important games he ever pitched, which is truly astounding.
His shining moment was the 2005 postseason, when he was instrumental in helping Houston reach their first (and only) World Series. In the Divisional Series against Atlanta, with the series tied at one game apiece, Oswalt pitched into the eighth inning of Game 3 and got the win, which helped the 'Stros advance to the NLCS where they were pitted against the defending NL champs.
In Game 2 versus St. Louis, with Houston needing a win after dropping Game 1, Oswalt shut down the Cardinals with seven innings of one-run ball. Back in St. Louis for Game 6 with the Astros looking to clinch their first pennant in franchise history, Oswalt was once again sublime, holding the Cards to one run on three hits through seven spectacular innings. Houston cruised to victory, and Oswalt was named NLCS MVP.
Unfortunately for him and the Astros, disaster struck in the World Series. The Chicago White Sox won their first World Series since 1917 by sweeping the Astros, just as the Red Sox had done to the Cardinals while ending their own World Series drought the previous fall. You could say the turning point of that series was Game 3 in Houston. With Oswalt on the bump, Houston took a 4-0 lead into the fifth inning and looked like they might just climb back into the series if they could finish off the win. There was still hope.
But in the top of the fifth, Oswalt unraveled. He imploded, allowing Chicago to send 11 men to the plate and score five runs. Houston eventually lost the game in 14 innings, a game they could and should have won. After that their title hopes vanished, and they were shutout in Game 4 as the White Sox popped champagne on their turf.
The Astros haven't been back to the playoffs since. Oswalt would make just four postseason starts after that and never pitch in the Fall Classic again.
Oswalt was one of those rare players who's great from the start and avoids the growing pains/adjustment periods that plague most young stars. He went 14-3 as a 23 year-old rookie in 2001, which gave him the league's best winning percentage. He also posted a 2.73 ERA that was 70 percent better than average when adjusted for league and park, and struck out six batters for every one he walked. Despite making only 20 starts, Oswalt should and would have been a slam dunk for Rookie of the Year most years. But 2001 was an exceptional freshman class, with Ichiro Suzuki taking home the AL award and MVP honors, something only Fred Lynn had ever done, while in the National League Albert Pujols had numbers that were Joe DiMaggio-esque. Pujols won the award unanimously, Oswalt finished a distant second.
But that perfectly embodies how poor Oswalt's timing was. His phenomenal early seasons were overshadowed by Randy Johnson and Roger Clemens. Then it was Johan Santana and Tim Lincecum. At times he was even obscured by his own teammates: Rocket and Andy Pettitte, Berkman and Jeff Bagwell and Craig Biggio. He got stuck in the "very good" class of pitchers that Dan Haren and Jon Lester have been living in for awhile. It's too bad he didn't get traded to the Phillies sooner--he joined the defending NL champs just as their core was beginning to show its age.
He did to get to be a part of one of the best rotations ever assembled, even if only for a season. He, Halladay, Cliff Lee, and Cole Hamels led the Phillies to 102 wins in 2011, a year which also marked the beginning of Oswalt's decline. Before the season, Oswalt looked like he might make the Hall of Fame one day. He had finished 2010 strong with the Phillies, leading the league in WHIP and coming in sixth in the Cy Young voting. Going into his age 33 season, it still seemed like he had plenty of gas left in the tank.. He needed a few more good seasons to pump up his counting numbers, probably needed to pitch into his late 30s at least, and if he got a World Series ring or two with the Phillies that would be icing on the cake.
None of that happened. Oswalt regressed to merely average in 2011, was terrible with Texas in 2012 and even worse with Colorado last year. The last two seasons were especially bad, as he got lit up for a 6.80 ERA in 26 appearances (15 starts). Like Berkman, Young, Halladay, Todd Helton, Oswalt did not go out on top. Few (Mariano Rivera, Ted Williams, Mike Mussina come to mind) do.
But those last few starts, ugly as they were, don't diminish what Oswalt was: a great pitcher for a full decade and one of his generation's finest. He may not be a Hall of Famer, but he's an easy choice for the Astros Hall of Fame and the (fictional) Hall of Very Good.