This weekend I watched some video of new Pirate acquisition Chris Jakubauskas. What I saw confirmed was the stat sheet said--basically, he's a low-leverage reliever, and if you need a spot starter, you could do worse.
Jakubauskas' basic M.O. is that he works quickly, chucking fastball after fastball into the zone. His heater is probably a notch better than you'd expect from his stats--it comes in at 90-93 MPH, so he's not a pure soft-tosser. He's able to get it into the zone very reliably, which explains why he walks so few batters, but he doesn't command it particularly well and he sometimes leaves it up, which explains why he allowed 15 homers in 93 innings last year.
Jakubauskas' curveball is filthy--it comes in pretty hard, at 78-79 MPH, but still has a ton of break. He mostly uses it as a change of pace, generally keeping it low and out of the strike zone. He also uses it pretty infrequently. He has a changeup that he uses very rarely--Fangraphs says he threw 73% fastballs, 21% curves and 6% changes last year, and based on what I saw, that seems about right. That seemed like a ton of fastballs to me, both from watching him and looking at the number, so I unscientifically looked around at the stats for a bunch of starting pitchers, and it looks like most of them throw around 60% fastballs, or fewer.
Jakubauskas has had a weird career. He was a position player at the University of Oklahoma, but he suddenly lost his swing, and he ended up trying to pitch. That got him gigs for a few years in the Frontier League, which is the league the Washington Wild Things are in, before he signed with the Mariners in 2007. He didn't even learn a changeup until 2008, which is probably why he throws so few of them. He might have some modest degree of success as a starter if he threw more changeups, but my sense is that he probably doesn't throw them for a reason right now, and it's not very likely the change will ever be a good pitch for him. Pitchers talk about learning new tricks a lot more than they actually do learn them.
Jakubauskas had an excellent spring for Seattle last season, and it wouldn't surprise me if he got people excited by pitching well for his first month or so in the National League, simply because he can throw strikes and he has a good breaking pitch. But I don't think that will last. Still, his two-pitch mix is pretty good, and he could end up being useful out of the 'pen. He's basically a cheap replacement for Jeff Karstens, and while I realize this isn't saying much, I think he has a good chance of being better, too.