Absolute zero is the coldest temperature theoretically possible, but this temperature cannot possibly be reached by any means because no matter how insulated the system, no matter how remote the nebula, nothing can be completely detached from the entropy of the universe. This is oddly comforting and is also the reason that even the Pittsburgh Pirates can have an all-decade team, even without a winning season. You can find the other entries in this series here.
Starting Pitcher: Oliver Perez, 2003-2006
Relief Pitcher: Mike Gonzalez, 2003-2006
Anyone that follows me on Twitter knows I struggled with this one. It's really hard to come up with a Pirate starter that had two good years this decade. Well, besides Kip Wells who, uh, no.
So what criteria do we use here? Kris Benson symbolizes all sorts of failed promise, had some decent years, and had a crazy wife who told us all kinds of things about them we didn't what to know. Zach Duke and Paul Maholm have both spent a pretty decent amount of time in a Pirate uniform this decade with some solid seasons, but some awful ones mixed in. Josh Fogg was reliably mediocre. Mark Redman, Ryan Vogelsong, and Jeff D'Amico were ... also Pirates during this span. Matt Morris was the straw that broke Littlefield's back. That might be the most productive thing any pitcher has done in this span.
In the end, I went with the pitcher that had the best individual season. What else can you do when no one shows any consistency? Despite all of his struggles before and after, Oliver Perez's 2004 season was probably one of the best in Pirate history. He struck out 239 hitters in 196 innings (11.0/9 innings) while walking 81 (3.7/9). For one year, all of his crazy arm angles and motions and weird pauses and preying mantis impressions and on-field celebrations were magical; on a team that only scored 680 runs he managed to win 12 games with his 2.98 ERA. He had nine starts with ten or more strikeouts, including three starts in a row in late July and early August (he went 1-2, including a 1-0 loss to the Braves were Russ Ortiz and John Smoltz combined on an 11-hit shutout; easily the most frustrating game I've attended at PNC Park).
Like Aramis Ramirez, Perez had some huge success at a young age (he was just 22 in 2004) and then everything went wrong. He didn't stay in shape over the winter, came into camp in 2005 with dimishied velocity and no control, and kicked a laundry cart part way through the season and broke his toe. By 2006, the Pirates had given up on him and put him in a package with Roberto Hernandez that returned only Xavier Nady. Flashes of brilliance surrounded by disappointment and ineptitude. The 2000s Pittsburgh Pirates in a nutshell.
On the relief side of things, Mike Gonzalez wins because he was just plain nasty. In four years with the Bucs, he held hitters to a 2.37 ERA, striking out 183 hitters in 155 2/3 innings. His 2004 season was otherworldy; in 43 1/3 innings he struck out 55 hitters, walked six, gave up two home runs, had a 1.25 ERA, and a 0.877 WHIP. In a decade of roller coaster closers, from Mike Williams to Jose Mesa to Salomon Torres to Matt Capps, Gonzo went 24/24 in save opportunities in 2006. Awesome.
Honorable mentions: A lot of the guys mentioned above deserve a spot here, but I want to specifically mention Salomon Torres. He came out of nowhere in 2002 after his big league career had been dormant for five years and gave the Pirates an excellent 5+ seasons with the club mostly out of the bullpen. His three-year run from 2004-2005 where he made no fewer than 78 appearances and pitched at least 92 innings out of the pen in each year were incredible, both for his durability and effectiveness. Most of all, he loved being a Pittsburgh Pirate because of the second chance they gave him when no one else would. He loved Pittsburgh so much he actually considered retiring when they traded him to Milwaukee prior to the 2008 season. You'd be hard pressed to find a player that enjoyed both Pittsburgh and the Pirates as much as Torres did, and he pitched well to boot.
Dishonorable mentions: Too many to list. Pretty much everyone that pitched for the Pirates in the last ten years qualify here for one reason or another.