Tigers Starting Rotation Thoughts

Detroit TigersI was thinking about the starting rotation for the Tigers and how lucky they really were in ’06 to have a pretty stable rotation. I know they lost Maroth but Zach Miner stepped in and held his own until the very end when Ledezma got a few starts. So having a total of 7 starters throughout the year was rather unique as most teams likely had a few more than that.

When looking at who was going to be the Tigers #1 starting in ’07 I started wondering what being #1 really means, if anything at all. My classic understanding of what a #1 starter was vs #2, 3, etc was that you had your best guy at #1. Doing so through the season, I thought, would pair up your # 1 vs the competitions #1 starter. But many issues get in the way of this actually happening whether it is off days or changing starters in/out due to performance or rest.

I wanted to better understand how often pitchers really faced each other for the Tigers so I took a look at 2006 statistics that I pulled from Retrosheet. I initially looked at how many unique starter/starter pairings were seen throughout the year, but this isn’t really fair as there are many teams the Tigers only played for one series leaving no chance of a repeat match up. So I then looked at each Tiger starting pitcher individually and weeded out the games where the pitcher started against the opposing team only once. This allowed me to then get a much better understanding of how often, within actual opportunities, a Tiger pitcher saw the same pitcher on a given opposing team thus getting some idea of how stable rotations are for both the Tigers and the teams they faced.

Here is what I found.

Here is a key for the columns on the data below:

  • Tp>1 – Teams played more than once
  • SaTp>1 – Starts against teams played more than once
  • Upf – Unique Pitchers Faced
  • Pf>1 – Pitchers faced more than once
  • %Re – Percent Rotation Effeciency

%Re is calculated by 1 – ((Upf-Pf>1)/SaTp>1). This measures the percent of starts where a pitcher saw the same opposing pitcher limited to only times where such a match up was possible.

Starting Pitcher Tp>1 SaTp>1 Upf Pf>1 %Re
Kenny Rogers 8 27 19 7 55.56%
Justin Verlander 8 23 19 7 30.43%
Jeremy Bonderman 8 25 21 3 28%
Nate Robertson 9 25 20 4 36%
Zach Miner 4 8 6 2 50%
Mike Maroth 2 4 4 0 0%
Wilfredo Ledezma 1 2 2 0 0%

For Miner, Maroth and Ledezma these don’t really mean much as they had so few starts but for their other starters these numbers were rather low. Each stable rotation member on the Tigers had roughly the same number of chances to start against a team more than once as well as roughly the same number of times it actually happened but Kenny Rogers faced only faced the same pitcher 55.56% of the time.

This is only looking at the percentage of repeat match ups and not whether we actually got #1 vs #1 match ups. A teams #1 guy tends to change throughout the season and sometimes it works out even when you don’t get it. For instance, and one of my favorites from 2006, was the Miner vs Liriano match up that happened twice and Detroit won both.

What factors should go into making your rotation at the beginning of the year? I’m not really certain on that one. I looked at Home vs Away and personally looked at many other statistics that should go into the rotation and nothing is all too compelling.

I’m curious as to every one else’s thoughts as to what makes a good starting rotation?

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5 Responses to Tigers Starting Rotation Thoughts

  1. Kurt says:

    In an ideal world, all your starters start the same amount of games, but the first and second starter of the season start the 161st and 162nd game so maybe you’d want the top 2 to get extra starts. But it really doesn’t work like that anyway, with skipped starts or skipped starters.

    And then based on the fact teams have different off days and weather cancels games, and you really can’t try to match 1 against 1, 2 against 2, or whatever, I don’t really think there’s a purpose to putting your top 5 in order.

    I think it’s more trying to mix up the type of pitchers opponents will see in a 3 game series, be it lefty, righty, lefty, or power, finesse, power, whatever. I think you still try to get your best guys pitching first, but a month into the season, mismatches are already occuring anyway.

  2. Eric Jackson says:

    Hey Kurt, I agree with you that overall it can be fruitless to put too much into the order. I think my point is that every year many folks make this a big deal, your #1 starter, etc.

    Also setting it up to have you #1 guy against the other teams #1 guy also takes participation by all teams involved. This isn’t too likely and if I was managing a low-on-talent team where each one of my pitchers was below the opposing pitcher it would be worth it to switch my lineup. I would put my worst guy against the opposing teams best and have my best against their worst. I might concede a few games but maybe a better chance at winning more.

    Since either of those outcomes are unlikely to actually happen, then maybe there are things that would make more sense to base your line up on. These would be factors that don’t change and aren’t dependent on the other team. Home vs Away, which away fields a pitcher will see, there are probably many more.

  3. Lee Panas says:

    I don’t think #1, #2, #3, etc matters very much for the reasons you stated. I agree with Kurt that managers worry more about alternating lefty/righty and hard/soft. Being the #1 starter on opening day is a big deal because of tradition but after that I don’t think it matters. Match-ups seem to become more important in the playoffs.

    I’m glad to see somebody else using the retrosheet database. I’m really getting into that myself right now.

  4. Eric Jackson says:

    I’ve been having a blast with the retrosheet data. Really makes life pretty easy. Too bad it only comes out long after the season.

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