Dominican League Performance as Indicator of Future Value

At the end of October, the present author published a not entirely exhaustive study which considered to what degree success in the Arizona Fall League (AFL) either did or did not portend future major-league success. Specifically, I looked at those AFL pitchers who’d finished either among the top or bottom third of that league’s starters by strikeout rate — the justification being that strikeout rate (a) is not only a fairly reliable indicator of success, but also (b) becomes stable in relatively small samples.

Even more specifically, I did this:

To better understand how much pitcher strikeout rate in the AFL rate might inform future major-league success, I looked at AFL pitchers from 2005 to -09 who’d both (a) faced 70 or more batters (that is, the sample threshold at which strikeout rate becomes reliable for major-league pitchers) and also (b) made at least half their appearances as starts. Each year in the DWL there are about 25-30 pitchers who meet both those criteria. For each of the five years in question, I isolated both the top and bottom third by AFL strikeout rate, resulting in 43 “high strikeout” and 43 “low strikeout” pitchers (although it should be noted that Adam Bostick appears twice among the high-strikeout group, thus leaving the former group with just 42 different actual players).

Despite the fact that Arizona Fall League performance is largely ignored — or, when it is cited, couched in a surfeit of qualifiers — the results of the study indicate that those pitchers who perform well in the AFL are more likely to perform well in the majors. By a reasonable margin, it seems. Again, the findings hardly suggest that AFL performance ought to be utilized without any context at all, but merely that — so far as pitchers are concerned, at least — it appears to provide non-negligible information regarding future value.

Of course, the AFL isn’t the only extant fall or winter league. Indeed, a number of other players — prospects as well as veterans and journeymen — all participate in the various Caribbean Leagues, the playoffs for which are currently underway in their respective countries. “What?” I asked myself in the service of ignoring something much darker and foreboding in my life, “what might winter-league performance say or not say about a particular pitcher’s future value?”

To answer that question — or at least begin to answer it — I utilized a methodology not unlike that one noted in the AFL study mentioned above (the justification for which methodology is explained in greater depth within that original post). For the earliest five years for which Dominican Winter League (DWL) data is publicly available — in this case, from 2007 to -11 — I looked at DWL pitchers who’d both (a) faced 70 or more batters* and also (b) made at least half their appearances as starts. Each year in the AFL there are about 30 pitchers who meet both those criteria. For each of the five years in question, I isolated both the top and bottom third by DWL strikeout rate, resulting in 51 “high strikeout” and 51 “low strikeout” player seasons.

*While Russell Carleton identifies 70 batters faced as the sample at which strikeout rate stabilizes, that threshold also oughtn’t be regarded as a “magic number,” but rather (according to Carleton) “the point where a measure of reliability slowly crosses an only-somewhat-arbitrary line in the sand.”

I say “player seasons” because this method of isolating high- and low-strikeout groups doesn’t actually produce two separate samples of 51 discrete players each. Unlike with the AFL, it’s common for players (especially those native to the Dominican) to participate in the DWL over the course of multiple seasons. Right-hander Ramon Ortiz, for example, meets the criteria for inclusion in this study in each of the five years between 2007 to -11. As a result, there’s no means by which to ensure a totally even distribution of high- and low-strikeout pitchers. The inability to do so, however, oughtn’t alter the results significantly. In the end, one is left with 41 distinct “high strikeout” and 34 distinct “low strikeout” pitchers for the purposes of this study.

For reference, during their respective DWL seasons, the high-strikeout group produced a collective 22.3% strikeout rate; the low-strikeout group, a figure of just 11.1%.

Having arrived at the two distinct samples, I then utilized the leaderboard feature here at the site to find the major-league outcomes for all the relevant pitchers since 2008 — that is, the first full major-league season major-league following the 2007-08 DWL season which serves as the first of the five DWL years in this study.

Here are the 28 members of the high-strikeout group (out of 41 total) to have recorded at least one major-league appearance during that interval, sorted by RA9-WAR (that is, WAR calculated with runs allowed per inning innings, as opposed to FIP):

# Name Team G GS IP K% BB% xFIP- FIP- ERA- WAR RA9-WAR
1 Johnny Cueto Reds 194 194 1208.1 19.9% 7.3% 97 95 80 17.0 26.1
2 Ivan Nova Yankees 93 86 537.2 17.5% 7.8% 98 101 101 6.3 7.4
3 Alfredo Simon – – – 209 51 529.1 16.6% 7.5% 107 112 97 1.2 4.3
4 Wily Peralta Brewers 70 69 411.0 17.5% 8.3% 103 107 101 3.4 3.4
5 James McDonald – – – 131 82 512.1 20.0% 10.4% 112 111 110 3.2 3.1
6 Robinson Tejeda – – – 127 7 187.1 24.0% 13.0% 103 88 86 2.3 2.1
7 Fernando Abad – – – 196 6 179.2 19.4% 7.6% 110 107 94 0.5 1.4
8 Dustin Nippert Rangers 78 18 198.0 17.3% 11.1% 112 105 108 1.2 1.4
9 Rafael Perez Indians 276 0 256.0 17.3% 8.7% 90 90 96 2.0 1.3
10 Kyle Davies Royals 88 88 481.0 15.6% 10.1% 113 107 121 4.8 1.3
11 Claudio Vargas – – – 64 4 98.0 16.9% 8.9% 106 103 96 0.3 1.1
12 Aquilino Lopez Tigers 48 0 78.2 17.7% 6.4% 107 91 81 0.7 1.0
13 Everett Teaford Royals 45 8 106.0 14.3% 7.9% 109 127 103 -0.5 0.8
14 Scott Lewis Indians 5 5 28.1 15.4% 6.0% 110 125 81 0.1 0.6
15 Roberto Hernandez – – – 178 167 975.0 13.8% 9.0% 108 119 122 3.8 0.3
16 Wesley Wright – – – 361 4 299.2 22.1% 10.1% 95 107 104 -0.4 0.2
17 Joselo Diaz Rangers 1 0 1.0 33.3% 16.7% 149 115 0 0.0 0.0
18 Jose Capellan Rockies 1 0 2.0 22.2% 0.0% 41 24 97 0.0 0.0
19 Doug Mathis Rangers 45 6 87.1 11.5% 9.1% 110 120 107 -0.2 0.0
20 Evan MacLane Cardinals 2 0 1.0 0.0% 25.0% 182 488 230 -0.2 -0.1
21 Yunesky Maya Nationals 16 10 59.0 10.3% 8.0% 126 127 149 0.0 -0.3
22 Rafael Rodriguez – – – 21 0 35.1 7.7% 7.1% 111 127 128 -0.3 -0.4
23 Raul Valdes – – – 103 3 140.1 24.5% 8.2% 102 105 134 0.5 -0.8
24 Aneury Rodriguez Astros 44 9 91.1 17.9% 8.7% 122 126 135 -0.1 -0.9
25 Chris Leroux – – – 65 0 71.2 19.8% 10.5% 99 85 153 0.7 -1.3
26 Radhames Liz Orioles 19 17 85.2 14.2% 13.0% 135 144 171 -0.3 -1.4
27 Esmil Rogers – – – 192 43 421.0 18.7% 8.7% 103 105 129 2.5 -1.6
28 Jorge Sosa – – – 60 2 80.2 12.8% 10.9% 129 133 140 -0.9 -1.9

And here are the 15 members of the low-strikeout group (out of 34 total) to have recorded at least one major-league appearance over that time period:

# Name Team G GS IP K% BB% xFIP- FIP- ERA- WAR RA9-WAR
1 Brandon McCarthy – – – 119 119 736.0 16.9% 4.8% 92 90 97 12.5 9.5
2 Greg Smith – – – 40 40 229.1 14.5% 11.3% 121 118 105 1.6 2.8
3 Francisley Bueno – – – 56 0 60.1 12.9% 4.7% 109 90 76 0.5 1.0
4 Luis Perez Blue Jays 78 4 112.0 20.2% 9.2% 93 98 108 0.6 0.2
5 Adalberto Mendez Marlins 5 5 24.2 10.1% 11.0% 154 186 125 -0.5 0.1
6 Jose Capellan Rockies 1 0 2.0 22.2% 0.0% 41 24 97 0.0 0.0
7 Henry Sosa Astros 10 10 53.1 16.5% 10.0% 117 125 138 0.1 -0.1
8 Josh Banks – – – 24 18 112.0 10.7% 8.1% 122 141 142 -1.0 -0.5
9 Cesar Valdez D-backs 9 2 20.0 13.4% 10.3% 113 112 180 0.1 -0.6
10 Frankie de la Cruz – – – 20 1 25.1 12.0% 17.6% 151 140 203 -0.3 -0.6
11 Hector Noesi – – – 97 48 362.2 16.4% 8.2% 114 124 131 0.1 -0.8
12 Ramon Ortiz – – – 45 8 88.2 13.7% 9.7% 123 146 144 -0.9 -1.1
13 Lenny DiNardo – – – 16 7 44.1 8.7% 12.1% 126 134 200 -0.2 -1.5
14 Jorge Sosa – – – 60 2 80.2 12.8% 10.9% 129 133 140 -0.9 -1.9
15 Julian Tavarez – – – 94 0 89.2 19.0% 12.6% 101 97 118 0.1 -2.0

Some observations from the data:

• Among the Dominican League’s high-strikeout group, 28 of 41 pitchers (68%) have recorded at least one major-league appearance since 2008. Among the low-strikeout group, only 14 of 34 pitchers (41%).

• Among the high-strikeout group, 16 of 41 pitchers (39%) have produced a positive WAR figure in the majors since 2008. Among the low-strikeout group, only 5 of 34 pitchers (15%).

• Among the high-strikeout group, 5 of 41 pitchers (12%) have produced a strikeout rate above 18% (i.e. the league-average rate since 2008) while working as a starter in the majors (minimum five starts). Meanwhile, 0 of 34 pitchers (0%) from the low-strikeout group have done the same.

• The median pitcher from the high-strikeout group has produced -0.3 RA9-WAR since 2008. The median pitcher from the low-strikeout group hasn’t appeared in the majors, but would (theoretically) have produced something worse than Julian Tavarez’s -2.0 RA9-WAR.

• Here are the top-10 DWL seasons by strikeout rate from 2007 to -11 among pitchers who faced at least 70 batters and registered at least half their appearances in a starting capacity:

# Player Year IP TBF K%
1 Everett Teaford 2012 23.2 91 32.0%
2 Fabio Castro 2010 51.0 212 28.8%
3 Joselo Diaz 2008 22.1 99 28.2%
4 Johnny Cueto 2007 31.2 132 28.1%
5 Hiroshi Kisanuki 2008 19.0 80 27.5%
6 Scott Lewis 2008 22.0 97 26.8%
7 Nerio Rodriguez 2010 43.1 176 26.7%
8 Yunesky Maya 2010 41.0 159 26.4%
9 Kenji Otonari 2012 23.0 103 26.2%
10 Aneury Rodriguez 2012 32.2 125 25.7%

And here, for some reason, are the 10 worst such seasons by that same criteria:

# Player Year IP TBF K%
1 Jose Mercedes 2010 17.0 73 4.1%
2 Lindsay Gulin 2009 17.2 80 5.0%
3 Hector Carrasco 2009 20.2 101 7.0%
4 Josh Banks 2010 37.0 157 7.0%
5 Sam Narron 2008 14.1 70 7.1%
6 Sam Narron 2009 41.2 182 7.7%
7 Jose Lima 2009 31.0 141 7.8%
8 Andy Van Hekken 2010 19.2 86 8.2%
9 Ramon Ortiz 2007 19.1 79 8.8%
10 Jose Capellan 2009 25.1 124 8.8%

Notably, two of the best 10 DWL seasons between 2007 and -11 were produced by Japanese pitchers. Both have remained active in the NPB through 2014.

*****

Conclusions
As was the case with the Arizona Fall League, it appears as though pitchers who produce high-ish strikeout rates in the Dominican Winter League are more likely than those who record low-ish ones both to (a) make a major-league appearance of some sort in subsequent years and (b) record a positive WAR figure in the majors in subsequent years. Success of this sort in the DWL does not appear to guarantee success in the majors. (The median sort of pitcher from the high-strikeout group has basically been replacement level in subsequent major-league seasons.) That said, it’s a more positive indicator of future value than finishing among the DWL’s lowest-strikeout group.

Finally, below are the 12 pitchers who comprise the high-strikeout group from the 2014-15 Dominican Winter League season. Pitchers are listed with 2015 age and club. Again, this is the sort of pitcher who went on to make a major-league appearance in 68% of cases and to produce a positive future WAR in 39% of cases.

# Player Org Age G GS GS% IP TBF K%
1 Radhames Liz Pirates 31 5 5 100.0% 23.2 92 31.7%
2 Randall Delgado D-backs 25 7 7 100.0% 33.0 138 29.7%
3 Miguel Almonte Royals 22 4 3 75.0% 19.1 73 25.9%
4 Chris Leroux Yankees 31 5 4 80.0% 16.1 70 25.6%
5 Asher Wojciechowski Astros 26 5 5 100.0% 20.1 87 25.2%
6 Liam Hendriks Blue Jays 26 6 6 100.0% 33.1 133 24.0%
7 Andre Rienzo Marlins 27 6 5 83.3% 18.0 84 23.8%
8 Nick Additon Brewers 27 6 4 66.7% 20.0 82 23.2%
9 Merrill Kelly Korea 26 6 6 100.0% 22.0 103 22.3%
10 Mitch Atkins Rangers 29 11 11 100.0% 46.0 193 21.8%
11 Amaury Rivas N/A 29 7 4 57.1% 28.1 111 21.6%
12 Sugar Ray Marimon Braves 26 5 5 100.0% 23.0 98 21.4%





Carson Cistulli has published a book of aphorisms called Spirited Ejaculations of a New Enthusiast.

9 Comments
Oldest
Newest Most Voted
Inline Feedbacks
View all comments
Chris Mitchellmember
9 years ago

In addition to stabilizing quickly, K% is also the metric that’s most predictive of MLB success for pitchers facing inferior competition according to KATOH.