No lefties, no difference for Fish

With Andrew Miller officially to start the season in Triple-A, the Marlins will head into Opening Day without any left-handed starters in their rotation. The team still has two lefties in the pen in Dan Meyer and Renyel Pinto, but of course, those guys can’t pitch (ideally) until the sixth inning. Won’t the team be in trouble having to face such talented lefties as Ryan Howard, Chase Utley, Brian McCann, and Raul Ibanez? Let’s dive into some numbers to find out.

In 2009, the Marlins faced lefties in 44% of their PA that did not end in an intentional walk. Since 2007, that figure is 39.4%. I did a weighted average (5/4/3 for 2009 on down to 2007) of the three percentages (weighted also by PA) and got a weighed average of 40.2%. That’s a nice and even number to use for an estimate of 2010.

But we only want to deal with starters, and some of those PA will end up in relievers’ hands. So let’s make another assumption: PA versus lefties and righties are distributed the same between starters and relievers. In other words, both starters and relievers will face lefties a projected 40.2% of the time. How many PA can we expect from our starters? Doing the same method as shown above, I get a projected percentage of 62.5% of PA going to our starters, a raw total of 3929 PA.

OK, let’s make one final assumption (I’m stretching things for the purpose of making this a quick study). Let’s assume that lefty and righty starters will receive the same distribution of lefty PA (something I know is not true, but probably is not too far off). With that, what would be the difference between having an all-righty staff and a staff populated by only one lefty (the Marlins likely would not have played both Miller and Sean West). Well, first we need to presume the number of PA that those two different pitchers, one righty like Clay Hensley or Rick VandenHurk and one lefty like Miller or West, would have taken up.

Last season, the Marlins got 350 innings from Sanchez, Miller, West and a tandem of the team’s worst starters/long relievers. Assuming a 1.2/1 ratio (just a wild guess) of innings to 4th and 5th starters respectively, that puts us at 160 innings going to 5th starter types. At 160 innings, you would probably expect something like 720 PA (around 4.5 PA/IP) given the quality of pitcher. Last season, those pitchers gave up 4.55 PA/IP, for comparison. In those 720 PA, we’d expect those starters to face 40.2% lefties, or 289 lefties. What’s the difference between a righty and lefty facing a lefty batter 289 times? Based on the R/PA I established in the relief splits article, the difference for one PA for an average pitcher would be 0.0157 runs per PA. I can’t hazard a guess on what that would mean for a poorer pitcher, but perhaps something like 0.018 runs per PA? Whatever sounds reasonable to you.

That difference over 720 PA is 11.3 runs. With the bump for poorer quality, that’s 13 runs. That’s around a win, which is decently significant, but not earth-shattering, I suppose. And of course, that considers that we have that righty in the entire year. We all know that that fifth spot does not stay static the whole season, and we would probably expect to see a guy like Miller or West show up at some point due to injury or ineffectiveness. If that’s cut by even a quarter of the amount, then we’re looking at a paltry eight or nine run difference. For a comparison, that’s a little more than the difference between having Dan Uggla’s offense and Cody Ross’ offense last season. Which is to say, probably not that much at all.

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  • JoeA.


    It’s good to see the Marlins send both West and Miller down to the minors where they can finish their development in a less pressure filled environment. I hope it’s not too late for them. I hate to keep beating a dead horse, but I hope this is an indication they finally learned their lesson and wont promote Stanton prematurely just because he crushes it in April.

    • Michael Jong


      Hopefully the time in the minors can help fix any issues those two have. I think West’s “control problems” were just fluky, but I’m glad he had them and convinced the team to send him to the minors, where he probably should have started. It’s Miller that concerns me the most. He’s re-tinkering with his delivery and reverting it to it’s form from his time in UNC. I hope this brings good things, but it’s getting increasingly difficult to believe. Let’s cross our fingers.

  • David C.

    It is worth pointing out to anyone worried about the platoon differnce that the five most likely starter candidates (Johnson, Nolasco, Sanchez, Volstad, Hensley) are a combined 14-11 with a 4.12 ERA and a 7.6 K/9 Ratio in 207.1 innings against the Phillies. While this isn’t mind-blowingly good, it is still very serviceable.

    It is also worth pointing out that Sean West and Andrew Miller both showed extreme reverse platoon splits last year (i.e. they did much better against righties than against lefties) although I don’t know if that is indicative of their true splits whatever they may be.

  • John Herold

    While it’s true Sean Wests results were that of a reverse split last year (1.84 WHIP v.s. LHB, 1.48 v.s. RHB), that was because of an extremely high BABIP and LHB (.425, .299 against RHB).

    He had a very good 3.00 BB/K against LHB (Just 1.41 v.s. RHB) and a 3.77 FIP (4.63 v.s. RHB). Interestingly enough in regards to an article I posted before, he also had a 51% GB rate against LHB but just 38% against RHB, but we’re also dealing with very small sample sizes here. But yeah, his peripherals suggest that there won’t be a reverse split going forward.

    Andrew not so much. His career FIP against either hands is near 1:1. What’s interesting is, he strikes out a ton of lefties (9.73) but also walks them at a rate Pinto would be jealous of (6.99!). Meanwhile, he strikes out righties at a below average rate (6.38) but his control is a lot better (4.45, it’s sad when that can be considered better). So his BB/K against righties and lefties is near identical even though he gets to the result in two very different manners.

    • Michael Jong

      John, thanks for pointing that out re: West. As for Miller, it’s worth noting that, all other things equal, you would want a guy with more K’s and BB’s over another guy with less of those things and the same K/BB. Even though Miller’s K/BB vs. lefties and righties are very similar, he’s better versus lefties because of the higher K’s and BB’s. A better measure may be K%-BB% (no intentional walks, of course).

      Versus lefties: 6.8%
      Versus righties: 5.1%

      Even though the K/BB is better versus righties, he still comes off looking worse when look at differential. Go ahead and check out Tom Tango’s explanation for more, he does a very good job of showing why differential is more telling.

      Nevertheless, I think Miller’s problems are on balls in play, and it may be an actual serious issue. If he’s someone who consistently gives up more than the average hits on BIP, then he may indeed be someone who isn’t major league worthy, especially if he can’t make it up by limiting walks or racking strikeouts.

  • John

    It pains me to say it, but in my heart of hearts, I believe Miler to be a bust at this point.