You’ve heard the narrative. Homer Bailey’s home/road splits are fairly pronounced this season: a 2.41 ERA on the road, 5.16 at home. A .249 wOBA allowed on the road, .370 at home.
This isn’t just a recent phenomenon either. In his career, Bailey has a 5.13 ERA in 334 innings pitched at home, and a 3.83 ERA in 296 innings pitched on the road. That’s a fairly big sample, and the comparison is stark.
Given this, and assuming the Reds lock up a 1 or 2 seed in the National League playoff structure, are they crazy not to let Bailey start one of the first two games on the road?
There’s a conservative philosophy that’s relatively unspoken yet fairly prevalent in sports, which dictates that managers and coaches should not deviate from the norm, as the risk is too great for the potential reward. If a manger goes out on a limb and makes an unconventional decision, even if his decision is based on legitimate data he will receive the blame should the method fail.
On the other hand, if he sticks to the status quo and the team loses, the immediate blame will go to the players and their execution. Obviously the coach gets some of the blame, especially if the losses begin to mount, but it’s a much safer strategy than the alternative.
This applies here. Imagine that the Reds did start Bailey in game two. Many people would applaud the move, citing Bailey’s splits and praising Dusty Baker’s bold decision making. However, much of the mainstream media would criticize the move because teams don’t generally mess with their rotation order in this way. Leading up the game, the story would be how the Reds decided to start Bailey, even though Mat Latos has been dynamite recently, even though Bronson Arroyo is a seasoned vet with playoff experience.
If Bailey pitched well, the Reds would have a good chance to win and everyone involved in the decision would avoid criticism. But this would also be the case if the Reds sent out Latos or Arroyo, who also have a good chance of pitching well. And in a one game sample size, can we really say we’d expect Bailey to pitch that much better than the other two?
Imagine if Bailey has an off night. Media would be relentless. All the pressure that was put on Bailey, and on those responsible for the decision, would become a burden for the duration of the series. What ifs would abound. Is it worth the potential, probably slight advantage gained by rearranging the rotation?
To be honest, and this is only my opinion, but I have feeling that arguing about rotation order is a lot like arguing about batting order. Yes, you want to optimize performance whenever possible, but as long as you’re making relatively defensible decisions, the difference between slight variations is very small.
At this point in the season, the four guys who will be starting for the Reds in October are set. The particular circumstances under which each man will pitch may vary slightly, but in the long run, night by night performance will be determined more by random variation, and not manipulations made by the manager.
The other thing to consider is, are these splits really legitimate. You could argue that most of Bailey’s problems at home stem from the longball, where he allows a 1.36 HR/9, versus 0.79 on the road. This could be attributed to GABP’s homerun friendly nature.
However, even shorter fences and the occasional wind gust isn’t going to create that discrepancy. On average, one out of every ten fly balls will leave the yard (a rate of 10%). In 2012, Reds starters are allowing a homerun-to-flyball percentage of 11.7 at home. Bailey’s GABP rate is 18.4. His career HR/FB % at home is 13.2. These numbers are inflated. Is it something that Homer Bailey specifically does that others aren’t doing? Does he just naturally allow a greater number of fringe flyballs that simply have a better chance of going out in GABP? It would take a lot more research than I’m currently capable of doing to determine an answer, but my initial reaction would be no, he doesn’t.
If you look at xFIP, which is fielding independent pitching that’s adjusted for ballpark tendencies, you can somewhat isolate Bailey’s performance to consider only results over which he has the most control. In a sense, it eliminates some of that random variation due to environment. In 2012, Bailey’s home/road split in xFIP is 4.16/3.82. Much less pronounced that his ERA or HR splits. For his career he’s 4.21/4.11. Again, hardly a significant difference.
On the heels of Bailey’s remarkable performance last night, you’re going to hear even more talk about the Reds giving Bailey a road start in the first round of the playoffs. While I’m all for making decisions based on objective analysis, I think I would side with the Reds, should they decide to keep Bailey as the #4 guy. And I think they will.