Let's be fair to Aaron Cook: he had his moments. Well, he had his moment. On June 29, facing off against Seattle, Cook retired 26-of-28 batters and doubled up one of the two he missed to record an 81-pitch complete game shutout. It was pretty awesome, and one of the few bright moments on a road trip that, in many ways, spelled the end to Boston's season.
Other than that, though, it was a pretty bumpy ride for Cook, who can only really be blamed for being what he is: a replacement pitcher. A sixth man depth option who you want to have in the system, but never want to see on the team. Unless you've given up on the year and are just interested in statistical anomalies like a 1.91 K/9.
No, really, that's a thing. Look at it.
On a contending team, Aaron Cook is the guy they turn to to keep the Zach Stewarts (or Charlie Zinks, Kyle Weilands) of the world out of games. They provide that buffer so hat, when injury comes knocking, it's not an unseasoned rookie floundering his way through three innings that gets the call, but a more stable performer who can maybe get some ground balls and let the defense do the work.
Was Cook consistent in that regard? No, because if he were he'd be a fourth starter on some team. He finished the season with a typically high ground ball rate, but there were plenty of nights where he went out and just threw meatballs. Giving up 15 homers in 18 games is rarely a recipe for success, and Cook was not an exception to the rule, finishing the season with a 5.65 ERA, averaging just over five innings per game, and inspiring a great deal more frustration and derision than appreciation.
But really the only problem with Cook was that he made 18 starts instead of four or five. With four or five, Cook can be an asset, particularly if the rotation can be shifted so he's facing the right teams. When a pitcher makes the hitters do the work by throwing strikes, it makes sense that they'll have a tendency to make bad teams look bad and good teams look good. Of course, it might sound a bit ridiculous to say that the ability to make bad teams look bad is some sort of positive trait, but we've all-too-often seen a flamethrowing ace come out, miss spots, walk batters, and then get wrecked for five runs against a lineup that before that game may as well have left their bats at home.
Unfortunately, the Sox were not a team that needed an Aaron Cook this year, but one that needed an actual rotation, and that need exposed Cook for what he is not. In a better year, we may have been able to appreciate having him there as a security blanket for a farm system lacking high-level pitching talent. So let's keep that in mind when the next opportunity comes to tar and feather him.