Now, he's starting the Cubs' playoff opener on Wednesday at 5:30 p.m. CT on TBS, winning out over ace Carlos Zambrano and big-ticket midseason acquisition Rich Harden. The former closer has come a long way since battling for a starting job in Mesa, Ariz.
"We put him in the third hole, third starter coming out of Spring Training," manager Lou Piniella said. "So that meant that we felt pretty good about Ryan having a good season for us. [But] he's probably [exceeded] our expectations. Seventeen wins, been very consistent all year. ... So, obviously, we're quite pleased. But we felt that he would have a nice season for us."
When Dempster bid farewell to starting pitching, it wasn't a particularly sweet parting. Two years removed from a rough 2003 season in the Reds' rotation, he made six ill-fated starts for the Cubs at the start of '05. He walked nearly as many batters as he struck out and won exactly once.
So, while Dempster's move to the bullpen after those six games was more about the team than about him, it's fair to call it mutually beneficial. He enjoyed 2 1/2 mostly successful seasons as the man in the ninth inning before sliding back into his old job as a starter this spring.
And though he'd started in the big leagues before, it wasn't an easy transition.
"I knew it was going to be a long road," Dempster said. "It was going to be a tough season to go out there and try to make every start, just physically after what I've been doing the past few years.
"I felt like I worked really hard physically. Mentally, I felt like maybe I was a little bit smarter, had a better idea of how to pitch. Go out there and just focus on the task at hand, keep it one pitch at one time."
Dempster got off to an excellent start, earning a spot, going 10-4 with a 3.25 ERA in the first half. He was even better in the second half, improving in every way -- lower ERA, higher strikeout rate, lower walk rate, lower home run rate. He was good in the first half. He was outstanding in the second half.
Now, he's taking the ball to open the playoffs.
"Did I think I'd be sitting here starting Game 1 of the NLDS? Probably not," Dempster admitted, "but I'm glad to have the opportunity."
For the most part, Dempster has contained the Dodgers' most prominent hitters, though Andre Ethier holds a 5-for-11 (.455) mark against him. He's faced Manny Ramirez once, with the slugger reaching him for a double.
But it's not the matchups, or the second-half surge, that stood out to Piniella when he tapped Dempster. It's one stat: 14-3. That's Dempster's record at Wrigley Field. And it's a big part of why he's not only starting Game 1 but would get the call in a deciding Game 5 -- also at Wrigley.
The other indicators aren't so stark -- Dempster's ERA was 2.86 at home, not that much better than his 3.13 on the road. His strikeout and walk rates were actually better on the road. But that record was hard to ignore. Not that Dempster can explain it.
"I don't know," he said. "It's a great place to pitch. I know people talk about it being a little bit of a smaller ballpark and the wind blowing out. But I like the mound, I like the backdrop. It's comfortable, obviously, when you're in your own home ballpark and you've got the fans behind you. For whatever reason, things have worked out numbers-wise as far as wins at home. I feel like I've thrown just as good on the road as at home, but just things have kind of fallen into place here at home, and for all of us."