Baseball fans know not to expect too much from a 5th starter. All we're looking for is a guy who gives the team a chance to win. A league average pitcher is pretty much the most one can ask for out of that spot. In 2012, Tommy Milone was just that. He had some wicked home/road splits, but his overall line was not bad.
His signature stat was his 1.7 walk rate, good for 6th best in all of MLB. His strategy was simple: Minimize baserunners, let hitters put the ball in play, and let your defense work for you. As long as the flyballs stay in the park, they are easy outs. And pitching in Oakland (and Seattle, and to an extent Anaheim) makes that task a lot easier.
Let's take a look at his HR, FB, and BB stats:
|2014 - first 5||27⅔||37.50%||11.10%||1.3||5.2||3.9||5.43||5.86||150|
|2014 - total 6||35⅔||42.10%||8.30%||1||5.8||3.8||4.76||4.54||116|
Basically, in 2012 Milone was building a reputation a flyball pitcher who didn't allow too many of them to leave the park, and didn't walk any batters. His FB rate was 37.3%, 26th highest in MLB. High, but not extreme. His HR/FB rate of 10.7% was 55th from the bottom; again, pretty decent (surrounded by guys like Anibal Sanchez, David Price, Bronson Arroyo, and Ryan Dempster).
In 2013, things changed. His walk rate jumped from 1.7 to 2.25, from 6th in MLB to 36th in MLB. That in and of itself is not terrible. If you're Max Scherzer, you can easily live with a walk rate in that range, because you give up no HRs and you strike out an obscene number of batters. Baserunners die quick and painful deaths. However, if you're Tommy Milone, it's a different story.
The other thing that jumps out is that he became an extreme flyball pitcher, and more of those flyballs left the park. A 44% flyball rate is not going to be sustainable for him, especially if he is walking a lot of batters. Walks + homers = bad news, and we saw that recipe served up in Boston.
Milone is always going to be a flyball pitcher, and he's always going to give up homers. Pitchers can control home runs to some extent (look at Matt Cain for an extreme example of a flyball pitcher that doesn't give up home runs) but I don't think Milone is that guy. If people are launching balls in the air, a steady amount of those are leaving the park, and that's just the way it's going to be.
As to the reason for his decline in 2013, I have a few theories based on watching him pitch last year, and sitting in the stands last night. Last year he seemed to abandon his fastball, perhaps out of fear of "challenging" hitters with a very hittable pitch. Without the fastball his best pitch, the changeup, can't work. If he's afraid to come inside or throw strikes with the fastball he's toast (as is any pitcher in that situation).
Last night he mixed speeds very well, his fastball topped out at around 87 or so, his curve was around 73, change and cutter were in between, but they seemed to always vary by a few miles per hour. Just that slight variance (and consistent working in of all four pitches) may be enough to keep hitters off balance, but if his fastball can't find the plate then hitters will just sit offspeed and launch away.
If he can keep up with mixing pitches and speeds, he's not going to have to nibble as much, and the walks hopefully will go down.
His first five games this year showed a return to the lower flyball rate but an astronomical walk rate and an elevated HR rate. After yesterday's tour de force, his HR number looks good, but the walks are still troubling. I need to see the walks go down before saying he's back, and continue to keep an eye on his flyball rate. High 30's, we can probably live with. Mid 40's, probably not. But there's more to it than just walks, homers, and flyballs, and after a couple of more starts we can take a dive into his pitch type and location data and see why he could be successful in returning to his 2012 form (if it's not already obvious by then with the eye test).