Age-Adjusted Dominance Ratio (Part 2)

Friday, April 26 2013 @ 04:02 PM EDT

Contributed by: robertdudek

This year, I've made some adjustments to my Dominance Ratio (DR) lists. I've tried to put all the pitchers on an equal footing, analytically speaking, instead of trying to subjectively adjust for age, level, experience and performance. It's not perfect, but my motto as regards sabermetrics is: let the numbers take us as far as they can... but no farther. An explanation of the method can be found at the conclusion of this article, for those inclined to read it.

In part 1, I went through the spring 2012 top 10 list and discussed the progress of each pitcher. Now we move to the spring 2013 list. Keep in mind that since the season is only 3 weeks old, I expect a lot of change if/when another list is produced in a month. I looked at every minor league starting pitcher with at least 3 starts in a given minor league (a player performing in multiple leagues is NOT assessed on his combined stats); i.e. no relievers were included.

Notes: data through April 24th; ranking in the Sickels pre-2013 top 150 prospects list and BA top 100 pre-2013 provided in parentheses.

1. Tony Cingrani*. (#65 Sickels; #82 BA) The only repeat from the spring 2012 list. We've already discussed the newest member of the Reds rotation. He was promoted to the BA100 list this spring and appears to have the inside track for NL rookie of the year.

2. Rafael Montero. (NR Sickels, BA) Born in Higuerito, Dominican Republic. Unlike most Dominican pitchers, Montero didn't start his pro career until he was 20 years old. He has shown excellent stuff and control throughout and with his success at AA he will start appearing on more prospect lists very soon. Ranked #10 prospect in Mets organisation by Sickels.

3. Clayton Blackburn. (#83 Sickels; NR BA) Drafted in the 16th round in 2011 out of Santa Fe HS (Oklahoma); Blackburn found immediate success in both rookie and A ball and starts 2013 as one of the youngest pitchers in Advanced-A. It will be interesting to see if he is promoted to AA this season.

4. Jesse Biddle*. (#61 Sickels; #89 BA) The Phillies spent their 2010 1st round pick on a local high schooler. Biddle's career progression is typical for a highly touted high-school pitcher: steady advancement through A ball and up to AA. This season should tell us much about how good Biddle can be.

5. Archie Bradley. (#21 Sickels; #25 BA) Along with Ryan Bundy and Clayton Blackburn, the third high schooler from Oklahoma on these lists. Taken in the 1st round in 2011, Bradley is a tall righthander. His first full season was spent in A ball and was a success, though the walk rate was high. Bradley was promoted to A+, but bear in mind that he is the least polished pitcher, statistically speaking, on this list.

6. Alex Wood* (NR Sickels, BA) 2nd round pick 2012 out of University of Georgia. Moving up the ladder fast and no problems so far. Ranked #3 prospect in Braves organisation by Sickels.

7. Burch Smith. (NR Sickels, BA) 14th round pick in 2011 from U of Oklahoma. Smith started in advanced A in his first full season and put up good numbers in a hitter-friendly environment. Promoted to the Texas League to start this season. Ranked #17 prospect in a deep Padres organisation by Sickels.

8. Vidal Nuno*. (NR Sickels, BA) The longshot story. Nuno was drafted in 2009 out of Baker University in the 48th round! He struggled in full season ball, was released, then found work in the independent Frontier League. The Yankees plucked him from the independents and he has rewarded them with a solid 2012 and a great start at AAA this season. Not ranked in Yankees' organisational top 20 by Sickels.

9. Joan Gregorio. (NR Sickels, BA) Born in Santo Domingo, DR, Gregorio had a surprisingly poor short season A ball showing in the Northwest League, but perhaps we can chalk that up to acclimatization, both cultural and meteorological. He's off to a dazzling start at Augusta in the Sally league. Not ranked in Giants' organisational top 20 by Sickels.

10. Edwin Escobar* (NR Sickels, BA) The third Giants farmhand on the list, the Venezuelan from La Sabana has just turned 21 and has been on fire in the hitter-friendly California League. He spent 2012 in the Sally league where he put up respectable numbers. Ranked #18 prospect in Giants organisation by Sickels.

* denotes lefthander

Interesting names among the next 15: Roberto Osuna (TOR), Jarred Cosart (HOU) Taijuan Walker (SEA) Trevor Bauer (CLE), Danny Hultzen (SEA), Asher Wojciechowski (HOU).

Concluding Remarks

How many of you were familiar with at least half of these names? I wasn't until I wrote this article. This method doesn't know a thing about a pitcher's reputation, and not a thing about his mechanics or psychological makeup, except insofar as these are reflected in the numbers. And this is a good thing... I believe that numerical and observational (i.e. traditional) evaluation methods should be developed separately, and only synthesized afterwards.

Technical notes

The first step is to calculate Dominance Ratio(DR): the formula remains the same - strikeouts divided by (.5*(non-intentional walks plus Homeruns allowed) plus .3*hits allowed). Homeruns therefore have a little less than three times the impact of other kinds of hits.

The next step is to regress towards the mean to account for sample size. I do this by adding 100 Batters Faced (BF) of the average performance of the qualifying pitcher pool at each LEVEL. I similarly adjust the pitcher's age relative to the average of the pitcher pool at each level (A and Advanced-A are separated). For example, the qualified pitcher age average at each level is: A=21.33; A+22.37;AA=24.09;AAA=26.58. As a result, each pitcher is compared to his peer group at his level according to age and regressed DR.

The penultimate step is to combine the two measures to create an age-adjusted DR score. The final step is to create a single benchmark across all minor league levels: the pitcher's score is compared to the 31st best score at one of three level groupings: 1) AAA, 2) AA and 3) A/A+ combined. The result is that if we chose a list of the top 90, there would be 30 representatives from each group: level bias is thus minimized (because there is more scope to dominate in the lower minors, there tend to be more outliers there).

endnote: 5 most dominant SP=>3 starts WITHOUT regard to age: T Cingrani, J Gregorio, R Montero, L Caughel, E Escobar

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