There's a certain tendency in trades like the Adam Eaton-Hector Santiago trade to be a little bit disappointed in the return. Fans overrate their own players -- especially if they happen to number among the few competents on a bad team. But I find myself in this case really not sure what we actually gave up.
We know for sure Hector is an extremely decent person who seems genuinely to want everyone to share in his good fortune. And he throws a screwball, which obviously is awesome. In fact, I'd go so far as to say he's indisputably the best combination of terrific person/screwgie ever to grace the organization. Go ahead, try to dispute it.*
Anyway, there are a couple ways we can look at Santiago. First, his value is reflected in the trade. Adam Eaton is not an incredible talent and, as Jim summarized in his post, he's a guy who's got to make up for some limitations to be a long term major leaguer. It's probably not that far off to say that's more or less what the league thinks when it looks at Hector.
Second, we can do some amateur scouting, which in this case is a little tough. He's not a classic anything and has a major-league career because he's much more than the sum of his parts. I'd bet plenty that everything but his fastball graded out below MLB average. Which means to most scouts, he's a one-pitch pitcher in The Show. Which means he ain't staying long. Average velocity, a junkyard full of offspeed pitches and a big heart? It takes some imagination to see anything more than a cup of coffee at the major league level. Kudos to the White Sox for taking an interest.
And to their further credit, he's played well in the bigs. His assortment of stuff is so varied that all of his pitches play up. The book on him undoubtedly says, "Get ahead, sit on a fastball," but he's fouled that up because he's such a nibbler and he'll throw pretty much anything whenever. And he's plenty willing to just walk you rather than give up the extra-base hit.
That is, I don't think his command is poor. He just knows he's living dangerously with his hittable stuff. And it's an open question whether or not he can keep doing it. So far there's a huge difference between his peripherals and his ERA. That usually means regression is coming shortly. That's what the projection systems are banking on.
Third, there's the Don Cooper track record. Gio Gonzalez is basically the only pitcher who's come close to really burning the Sox since Coop took over as pitching coach. I didn't check that thoroughly, but I think pitchers the Sox have traded have had more major surgeries than above average seasons. Point being, they saw Hector as a potential major leaguer when most saw filler. And now they're saying maybe he's dispensable.
So, where do I fall? I want to side with the screwgie, call him a legit No. 3 and lament the loss of a very talented pitcher. But I think I have to go with Cooper and the projection systems. Much as I don't want to say it: sideshow, not iconoclast.
*You might be thinking, "What about Jack Harshman?" To which I scoff. You mean Jack "The Aptly Named" Harshman? Don't get me started.