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.