Now that the Reds have clinched a postseason spot, the biggest decision they have in front of them is what to do about the starting rotation in the playoffs. I have a pretty solid idea of what they will do, and I know what I would do (I’ll share that at the end), but I thought it would be interesting to look at what the sabrmetric statistics say they should do.

Sabrmetrics has shown that a pticher can control a few things. He can control how many batters he strikes out and how many batters he walks. He can control his GB/FB ratio and, to a lessser extent he can control his HR rate. Those are the numbers we’ll be looking at along with the advanced pitching metrics FIP and xFIP, which are mostly just compilations of the above numbers.

This season, eight pitchers have started a game for the Reds. They are (from fewest to most IP):

Pedro Villarreal
Greg Reynolds
Johnny Cueto
Tony Cingrani
Mike Leake
Bronson Arroyo
Mat Latos
Homer Bailey

Now, obviously, Villareal and Reynolds are not going anywhere near the postseason roster. So that leaves us with six players. Tony Cingrani would be a great option (he has the highest K/9 rate of the group), but he’s had back problems. Given that, and his rookie status, it’s hard to imagine him in the playoff rotation (though not in the playoff bullpen).

So now we are down to the same five pitchers we started the season with and one of them has to be cut.

Homer Bailey is the most obvious choice in this group. He’s fully healthy. His K/9, BB/9, and home run rates are all second best on the team, as are his 3.19 FIP and his 3.23 xFIP. So he’s in.

The second most obvious selection is Mat Latos. Latos would be the most obvious, but we recently learned he’s been pitching hurt for a while. Still, he’s been pitching and doing solidly. His K/9 is third on the team and he’s been very stingy with home runs. As a result, his FIP is team low 3.12. His xFIP is slightly higher at 3.57 (that actually puts him fourth in our group). But injury or not, given his track record, Latos is a good bet. He’s in.

Now it gets a little muddier. Cueto, Leake, and Arroyo all have issues. With Cueto, we have to worry if he’s really fully ready. Sure, he’s had two good starts since coming back, but they were against the Astros and the Mets – hardly playoff caliber squads. Leake and Arroyo are very similar. One brings a longer track record while the other has had better results this year.

If you look at what the advanced stats tell us, you have to take Johnny Cueto. He has stronger groundball tendencies than any other player in this group. His FIP (3.80) is second and his xFIP (3.23) is first. Cueto also tends to out perform these two numbers, at least partially because he is so good at shutting down the running game.

And so, as we all knew it would, it comes down to Leake vs. Arroyo. On one level, this is an easy decision. It’s certainly hard for me to imagine the Reds taking Leake and putting Arroyo in the pen. Arroyo is a vetran and an important part of the team. He has a long track record, etc., etc. But there is a case for Leake.

FIP likes Leake more than Arroyo (4.00 to 4.20). Their xFIPs are more or less identical as are their K-rates. Leake walks more batters, but Arroyo gives up more homers. In limited action, Leake has performed poorly out of the bullpen, but Arroyo has at least some experience with successful relief pitching, even if it was a long time ago. But really, they’re almost the same pitcher, which is not a bad thing even playoff teams struggle to find excellent 4th starters, and both Arroyo and Leake rank as something like league average pitchers.

The option about which we should not speak is the three-man rotation. I know someone will probably lobby for it. They shouldn’t. it doesn’t work. Yes, you can find select instances of pitcher going on short rest in the playoffs and doing well. That is called cherry-picking. If you look across the board at pitchers on short rest in the playoffs, what you find is that you are turing Johnny Cuetos into Mike Leakes and Mike Leakes into into Pedro Villarreals. Don’t do it. It isn’t worth it.

If I am choosing devoid of emotion, I take Leake over Arroyo because his results have been slightly better this year and I have more faith in Arroyo to provide value in relief. But really, as much as we’ll want to argue about thisl, there isn’t really an argument to be had. Unless you think Cueto shoudl be left out ofthe rotation, the only choice you have to make barely even qualifies as a choice.

If it were me, I’d have a rotation of Bailey, Latos, Cueto, Leake. I think the Reds will probably set it up as Cueto, Latos, Bailey, Arroyo. Either way is good. We’ve felt good about the pitching all year. Now is not the time to stop.