2010 Dominance Factors


We fans aren’t privy to any in-depth scouting reports like the 30 MLB teams are, so really all we have for information about our favorite minor leaguers is second-hand publications (Baseball America, etc.) and statistics. Stats are great fun and tell us a lot, but they lie when it comes to the minors. They lie like you wouldn’t believe. A tremendous amount of context is needed for them to be useful, covering everything from age to league to park, the whole nine. A 19-year-old with a 4.00 FIP in Double-A is more impressive than a 24-year-old with a 2.70 FIP in Single-A.

A few years ago, Brett Sullivan at Project Prospect developed a stat called Dominance Factor, which measures how “dominant” a pitcher was (based on strikeout, walk, and ground ball rates) relative to his age and the level he played in. Here’s the quick-and-dirty explanation of the formula and logic…

Dominance Factor, DF = (K% + 0.72*GB% – BB%)+ (Age Level Standard – Actual age)*7

GB% is multiplied by 0.72 because generally speaking, 72% of groundballs turn into outs. The Age Level Standards are basically the average age at a given level, and are 20-yrs old for Low-A, 21 for High-A, 22.5 for Double-A, and 24 for Triple-A … The stat doesn’t have any real analysis purposes because of the assumptions used for GB% and age, so it’s best used for reference. It’s still fun to look at, though.

For the second year in a row, Manny Banuelos posted the largest DF in the system, coming in at 72.1. He topped last year’s mark by 7.1, but Phil Hughes still holds the overall record thanks to his 86.0 DF effort with Triple-A Scranton back in 2007. Kinda puts in perspective how absurdly good Hughes was in the minors. Ivan Nova was a rather distant second to Banuelos at 55.0. The Double-A version of Adam Warren was right behind him for third (53.5), then Brett Marshall and the Triple-A version of David Phelps tied for fourth at 50.0. Unsurprisingly, various dreck like Wilkins Arias (-24.4), John Van Benschoten (-18.5), and Tim Redding (-12.8) populate the bottom of the list. It’s all about age relative to level.

Here are the 2009, 2008, 2007, and 2006 DF’s. The full 2010 chart is after the jump, but there’s a few things to know first: starting pitchers are in bold, players no longer with the organization are in yellow, and players eligible for the Rule 5 Draft are in blue. The K%, BB%, and GB% data all came from First Inning, and I intentionally omitted Josh Romanski because FI doesn’t have data for him. The average DF was 23.6 with a standard deviation of 20.2. That means the data is pretty well spread out. Anyway, table’s after the jump, I hid it for space and load time reasons.

Categories : Analysis, Minors


  1. KofH says:

    What do you do with a guy like Amaury Saint?

  2. Plank says:

    Thank you Austin Kearns. I have a feeling that trade will come back to bite us.

  3. The one problem I see with this stat is that it favors healthy guys. Brackman for example was hurt so his age reduces his dominance factor. It should be ((adjusted service time) / (service time))*7.

    • Ed says:

      It needs to be age. The younger guys in the minors might still be growing a little, and almost all of them are going to add muscle as they work through the system. That adjustment factor has at least as much to do with physical development than with experience.

      Also keep in mind that if a high school draftee and a college draftee put up the same stat line at the same level, the high school draftee is much more impressive. Going by service time doesn’t factor that in.

    • Sayid J. says:

      A stat that favors healthy guys is a stat I can agree with.

  4. Ed says:

    Phil Hughes still holds the overall record thanks to his 86.0 DF effort with Triple-A Scranton back in 2007. Kinda puts in perspective how absurdly good Hughes was in the minors.

    Hughes pitched 28.2 innings in AAA that year. I would think that’s more a case of a small sample size than a true skill level.

  5. Esteban says:

    Should you be allowed to have a negative dominance factor? Shouldn’t that be on a different scale, like ineptitude factor? Who has the record ineptitude factor?

  6. Dick says:

    What was Brien Taylor’s DF before he blew out his shoulder?

  7. The first guy I searched for was Kei Igawa. I laughed

  8. YankeesJunkie says:

    Meh, these are nice to look at for fun and games, but I am surprised they are not adjusted as well for K/BB rates somehow and a multiplier factor for IP. However, this shows how dominant Banuelos 2010 campaign was and there is a good chance he will be up there again next year.

  9. China Joe says:

    Doesn’t it seem odd that AA Brackman is ranked so much lower than A+ Brackman? He had a small drop in K%, but a huge drop in BB% and his age relative to level jumped up.

  10. Jake H says:

    Manny B is a beast. I am hoping that they keep him at AA all season to get his innings.

  11. JobaWockeeZ says:

    Hmm why hasn’t Heredia gotten much looks with his dominating performance?

  12. B-Rando says:

    That K% from ManBan tells the story of how dominating he was. 34% is pretty ridiculous.

  13. RobC says:

    Is there an avg DF for league comparision or age comparision?

  14. Sal says:

    Lee 6/140 see google search Sporting news article

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