I’m going to present some stylized facts about pitching:
Pitchers can be divided into two groups: guys with rotation stuff and guys with bullpen stuff. That said, anybody can be used in any role you want. The guys with rotation stuff are the guys with more quality pitches and better endurance to keep them going past pitch number 75. The guys with bullpen stuff have fewer quality pitches and less endurance.
If you use a guy with rotation stuff will still do better as relievers – they can go “all out” every pitch and don’t have to worry about getting “figured out” the second or third time through the order. Take their OPS allowed as a starter the first time through the order and shave maybe 50 points off of it. That’s what you can expect as a reliever and along with that goes a drop in ERA of about a run.
On the other hand, if you use a guy with bullpen stuff in the rotation he’s really going to struggle. There’s a lot of sample selection bias here in trying to figure out just how much of a change there’s going to be – guys tend to stink as starters for a short time before being moved to the bullpen. You’ll notice, though, that a lot of guys with long careers in relief did begin as starters for a couple of years (like new closer Joe Nathan) Despite that, the differences seems to be a fairly consistent 2 run rise in ERA (Nathan had a 4.60 ERA as a starter, but a 2.33 ERA in relief).
Within these groups you’ll have guys with mediocre (4.50 ERA) rotation stuff who can be solid (3.50 ERA) relievers and guys who have bad (5.50 ERA) rotation stuff who can be mediocre relievers – i.e. garbagemen. If your guy with rotation stuff is at all better than mediocre, you’d say it’s kind of a waste to use him in relief – typically. You’ll have guys with solid relief stuff who would make bad starters (like Octavio Dotel) – makes a lot more sense to use him out of the ‘pen, he should at least be cheaper and easier to find. You’ll also have the occasional guy like Nathan with elite (2.50 ERA) bullpen stuff who could have been mediocre starters – but why? If you’re ever contemplating changing roles – it’s key to figure out whether you’re actually talking about a guy with rotation stuff or bullpen stuff. However, it seems like the typical approach is just to give guys who flopped as starters a try in the ‘pen to see just how much it improves their results.
Drew Smyly is a guy we have always felt and continue to feel has rotation stuff. He’s one of the ones we’d expect to have a starting-relieving split of about a run and in his brief tenure he does (3.79 ERA vs. 2.69 ERA). Since he was almost solid as a starter – that made him almost elite as a reliever. That leaves big shoes to fill in the ‘pen, but it’s hard to argue that it isn’t the better use of Smyly as an asset to move him into the rotation. We’re hoping Ian Krol – a guy that the Nats converted from starter to reliever in 2013 – is actually a guy with bullpen stuff and not rotation stuff. What do I mean by that? As a minor leaguer he was mostly a starter, with decent but unimpressive results (despite a young age and injuries). His “age-adjusted” Davenport Translation of those minor league numbers puts him at a projected ERA – as a major league starter – of approximately 5.00. If he’s actually a guy with mediocre-bad rotation stuff he’d only be a run better as a reliever – which is what the Nats actually got from him in half a season of relief in 2013 (3.95 ERA). If he’s actually a guy with solid-elite bullpen stuff he’d still show that same 5.00 ERA as a starter BUT as a reliever we’d get 3.00 – which is what we’re hoping for. Cross your fingers. The best relievers wind up being guys like Joe Nathan and Mariano Rivera (or maybe Ian Krol..?) who were almost good enough to start, despite quite definitely possessing bullpen stuff rather than rotation stuff.
The Tigers have a few other not-good-enough-to-start guys in the organization already that are worth considering for bullpen roles, at least for Spring Training. Casey Crosby has struggled mightily in Toledo – is it because he actually has bullpen stuff and not rotation stuff? I think it’s pretty clear that Luke Putkonen had bullpen stuff all along, now we’re just wondering how much of it he actually has.
The biggest related question last year was whether Rick Porcello would be better off in the bullpen or the rotation. I’d say that Tigers management is pretty well convinced that Porcello has rotation stuff – though his results to this point have been indicative of mediocre rotation stuff. He’d presumably be solid as a reliever – that is the norm – but guys with a 4.50-3.50 start-relief split are probably better off starting (though maybe not for World Series contenders). I’ve never been convinced of this… I still suspect that Rick Porcello is actually something more like Joe Nathan – a guy with elite bullpen stuff that’s just barely able to pass as a starting pitcher. My personal preference – though hoping any GM would take such a gamble is ridiculous – would have been to hold onto Fister, move Smyly into the rotation and – rather than sign Joe Nathan – make Rick Porcello the new closer.
I have been over this before, but the reasons why I think he has bullpen stuff rather than rotation stuff are pretty simple. Porcello struggles the second and third times through the order and Porcello has big L-R splits. John Smoltz and Dennis Eckersley are my two big examples of guys who were successful as starters and then successful as relievers – there is no sample selection because they didn’t flop and they appeared in a lot of games in both roles. Eckersley had a .635 OPS against as a starter the first time through the order. Smoltz had a .623 OPS against as a starter the first time through the order. Porcello has a career .645 OPS against the first time through overall and a .620 OPS against the first time through last season (and we do believe he is getting better from year to year). As a starter, he’s Eckersley/Smoltz the first time through the order. Max Scherzer has a career .668 OPS against the first time through, Verlander .629. Digest that for a minute. Obviously Porcello’s overall results are not like Eckersley’s or Smoltz’s or Scherzer’s or Verlander’s because the 2nd and 3rd times through the order the wheels come off. As Porcello has developed we have seen improvements, but he has been getting better and better the first time through the order rather than narrowing the gap between 1st and 2nd. I think Porcello just has bullpen stuff… and if he has bullpen stuff even if he’s barely good enough to start you’re still better off using him out of the ‘pen where he would be flat out amazing.
This is all in my head – obviously – but I’d peg Fister as a win better than Smyly as a starter and Smyly as a win better than Porcello as a starter. I’d also peg Porcello as the equal of Joe Nathan as a reliever. Given that Fister costs $3 million less than Joe Nathan, that money could have been used to hire somebody like Oliver Perez or Matt Thornton to replace Drew Smyly in the bullpen keeping the exact same overall budget. If they were to have gone along with my ridiculous plan (that I’ve been promoting for a year now) the 2014 Tigers would look 2 wins better on paper than they do right now, exchanging the risk that Porcello might only be a solid reliever rather than an elite one for the risks associated with Nathan’s age and injury history. Of course, the Tigers also wouldn’t have Robbie Ray and Steve Lombardozzi but at this point I think I’d much rather have the extra two expected wins.