2009 Minor League Stats Worth Tracking

A number of Rangers prospects who are expected to start the season in AA or AAA have a chance to impact the major league club in 2009.  If injuries, ineffectiveness, or trades at the big league level do not force the Rangers to promote a prospect, then adding a minor league player to the big club will likely only happen if the Rangers believe he will improve the performance of the major league team. 

Determining when a prospect is ready for a big league promotion is best accomplished by a combination of scouting and statistics.  Scouts and coaches (or Jason Parks and Zywica) can determine if a player has made adequate progress with his change-up or outfield defense or pitch recognition or whatever was deemed critical for the player’s development.  Statistics indicate whether a player’s skills are being efficiently converted to production.  One tool that is available for fans to track whether a prospect might be ready for the majors is major league equivalents (MLE).

The MLE concept was first described by Bill James in the mid-80’s and posits that there is a strong correlation between major and minor league stats.  During the past 20+ years, James and others have developed algorithms that convert minor league stats to major league stats and vice versa.  MLEs have proven to be almost as predictive of future major league performance as a major league player’s prior year stats.  A variety of web-sites provide custom tools for converting minor league numbers to major league numbers and vice-versa.  If you are interested, Dan Szymborski provides one of the more straightforward descriptions of how to calculate MLEs at 

Rangers prospects who might emerge as at least major league average players in 2009 are presented below.  Two things worth noting:
(1) There will likely be specific things that each of these players are working on that will keep them from posting optimal minor league numbers (e.g., Feliz will likely limit the use of his fastball in 2009 to develop his off-speed pitches).  This will effectively suppress the prospect’s stats.   
(2) Prospects are often promoted to provide them with major league experience so that they are better prepared to contribute in future years.  If that is the case for the 2009 Rangers, then it is likely that one or more players will be promoted before they can be expected to perform as a league average player (e.g. Elvis Andrus).

Presented below are the average performances of American League players by position in 2008 according to  I used the MLE calculator at to convert the ML average hitting numbers to AA and AAA equivalents.  There is not a good calculator for major league equivalents for minor league pitchers so I reverse-engineered the calculator used by Minor League Splits ( to convert the American League average starter and reliever numbers to AA and AAA equivalents.  Minor League Splits was the source of the career statistics that are listed after the name of each Rangers prospect.  Minor League Splits is also the source of the 2008 stats and MLEs that are provided for some of the players listed below. 

The combination of major league averages, MLE’s, and minor league numbers for the various prospects are used to provide some sense of what statistical weaknesses individual players can improve to enhance their chances of becoming league average or better players. 

Starting Pitchers
Major League Average – 1.39 WHIP, 6 K/9IP, 3 BB/9IP, 1 HR/9IP
AAA Equivalent – 1.25 WHIP, 6.7 K/9IP, 2.3 BB/9IP, 0.7 HR/9IP
AA Equivalent – 1.25 WHIP, 7.5 K/9IP, 2.2 BB/9IP, 0.8 HR/9IP

Near-Ready Rangers Prospects

Tommy Hunter – 1.18 WHIP, 5.8 K/9IP, 1.7 BB/9IP, 0.8 HR/9IP (career minor league averages)
Hunter’s first exposure to major league hitters wasn’t pleasant, but his early AAA numbers suggest that he is close to being ready for the majors.   Hunter’s 50+ AAA innings in 2008 translated to an MLE of 1.22 WHIP, 4.2 K/9IP, 1.8 BB/9IP, and 1.5 HR/9IP.  If he can decrease the homeruns and increase his strikeout rate, then Hunter should be ready to provide the Rangers with a league average pitcher. 

Derek Holland – 1.03 WHIP, 9.7 K/9IP, 2.5 BB/9IP, 0.4 HR/9IP
Holland’s minor league numbers indicate that he is on-track to be an above average major league starter.  If Holland can hit his career numbers while pitching in AA or AAA this year, then he would project to post numbers akin to the 2008 version of James Shields (~3.5 ERA, ~1.15 WHIP, ~8 K/9IP, ~3 BB/9IP).

Neftali Feliz – 1.13 WHIP, 11.2 K/9IP, 4 BB/9IP, 0.2 HR/9IP
In 45 AA innings in 2008, Feliz’ MLE consisted of a 3.16 FIP, 1.26 WHIP, 9.3 K/9IP, 4.6 BB/9IP, and 0.2 HR/9IP.  Except for the walks, those translated stats suggest that Feliz is ready for a spot in a major league rotation.  If Feliz can add a second plus offering to his repertoire while continuing to dominate AA hitters, then he will be ready for a starting role in the major leagues by 2010 at the latest.

Thomas Diamond – 1.35 WHIP, 9.5 K/9IP, 4.8 BB/9IP, 0.74 HR/9IP
Diamond’s career numbers, which are admittedly buoyed by his first two years in the minors, suggest that he is on-track to carve out a major league career.  The stat to watch in 2009 will be walks – if Diamond can drop his walk-rate to below 3 per 9 innings, then he has a legitimate shot to become at least an average major league pitcher.   

Relief Pitchers
Major League Average – 1.39 WHIP, 7.5 K/9IP, 3.9 BB/9IP, 0.9 HR/9IP
AAA Equivalent – 1.25 WHIP, 8.3 K/9IP, 3 BB/9IP, 0.6 HR/9IP
AA Equivalent – 1.25 WHIP, 9.4 K/9IP, 2.8 BB/9IP, 0.7 HR/9IP

Near-Ready Rangers Prospects
Pedro Strop – 1.23 WHIP, 11.7 K/9IP, 4.1 BB/9IP, 0.8 HR/9IP (career minor league averages)
Strop’s career walk-rate is high but the rest of his career numbers suggest that he can be an average to above average relief pitcher.  If he can remain healthy and drop his walk rate to ~3 per 9 innings, look for Strop to spend time in the Rangers bullpen in 2009.

Guillermo Moscoso – 1.08 WHIP, 9.5 K/9IP, 1.9 BB/9IP, 0.7 HR/9IP
Moscoso’s stats scream above-average starter. His repertoire and age relative to league suggest bullpen.  If Moscoso can remain healthy and post the same stats as a reliever in AA or AAA that he’s accumulated as a starter in the lower minors, then look for him to become an above average major league reliever in 2009 or 2010.
Beau Jones – 1.42 WHIP, 8.5 K/9IP, 5.0 BB/9IP, 0.5 HR/9IP
Jones’ career numbers include time as both a starter and reliever.  His 2008 numbers, which came primarily as a reliever, included a lower WHIP (1.30) and slightly lower walk-rate (4.3 BB/9IP).  If he can continue to push those two stat lines down in 2009, then it is likely that Jones will be challenging for a spot in the Rangers’ pen in 2010.

Brennan Garr – 1.36 WHIP, 10.2 K/9IP, 4.8 BB/9IP, 0.4 HR/9IP
Garr’s walk rate is the difference between being a candidate for the major league pen and being an after-thought in AA or AAA.  As with many of the pitchers on this list, Garr needs to improve his control in 2009 without sacrificing strikeouts or homeruns. 

Center Fielders
Major League Average – 269/334/412/746; 27 2B, 2 3B, 13 HR, 57 BB, 121 K
AAA Equivalent – 323/398/514/912; 39 2B, 7 3B, 21 HR, 77 BB, 112 K
AA Equivalent – 341/421/545/966; 39 2B, 7 3B, 23 HR, 84 BB, 110 K

Near Ready Rangers Prospects
Julio Borbon – 321/363/425/788; 32 2B, 2 3B, 7 HR, 29 BB, 62 K (2008 minor league averages)
Borbon’s numbers in Frisco (336/380/457/837 in 256 at bats) translate to an MLE of 272/307/352/659.  The MLE batting average would have placed Borbon as above average but the 307 OBP would have been almost 30 points below average in 2008.  If Borbon can improve his walk rate by 3-5% in 2009 while maintaining the high BA, look for him to be patrolling centerfield at RBiA by September.
Greg Golson – 265/310/411/721 (career); 286/337/440/777; 27 2B, 6 3B, 19 HR, 51 BB, 192 K (’08 est for 700 PA)
Golson’s 2008 OPS in 420 AA ABs was the highest of his career.  His walk-rate and power numbers don’t jump off the page, but they do suggest that he could be an average major leaguer.  As has been noted by others, Golson’s statistical flaw is his strike-out rate.  Assuming Golson maintains his career .350 BABIP, he could hit .310 and put himself on the prospect map in 2009 by simply reducing his strike-out rate to 20%.

Middle Infielders
Major League Average (SS and 2nd base) – 274/329/393/722; 32 2B, 3 3B, 9 HR,
AAA Equivalent – 325/389/473/862; 42 2B, 4 3B, 13 HR, 64 BB, 87 K
AA Equivalent – 346/414/503/917; 43 2B, 4 3B, 14 HR, 70 BB, 85 K

Near-Ready Rangers Prospects
Joaquin Arias – 293/319/401/720 (career minor league averages)
    ’08 est for 700 PA – 296/329/421/750; 22 2B, 13 3B, 10 HR, 30 BB, 79 K
Arias is a .290-.300 hitter with a good glove and not much else.  His slugging and OBP will likely keep him from being more than a bottom third starting SS or average utility infielder.  Assuming he begins the year in AAA, a sudden spike in his walk-rate could indicate that Arias is finally ready to become a major league shortstop.

Jose Vallejo – 292/345/425/760; 29 2B, 4 3B, 11 HR, 41 BB, 91 K (2008 averages)
Vallejo could take another big step up the prospect ladder if he proves that he can play shortstop and he increases his BA to over 310 without sacrificing his walk rate or power.  If successful, the resulting 310/365/450/815 line would look like what you would expect from an average major league shortstop playing in Frisco or Oklahoma.

Major League Average – 258/322/393/715; 28 2B, 1 3B, 12 HR
AAA Equivalent – 306/379/484/863; 39 2B, 1 3B, 20 HR, 67 BB, 108 K
AA Equivalent – 327/403/517/920; 39 2B, 1 3B, 22 HR, 72 BB, 106 K

Near-Ready Rangers Prospect

Max Ramirez –  317/424/521/945 (career minor league averages)
’08 est for 600 PA – 347/439/628/1067; 38 2B, 4 3B, 38 HR, 84 BB, 138 K
 Ramirez’ MLE in 2008 (269/339/442/781) would have placed him third in hitting among AL catchers with at least 300 ABs.  If he can catch, Ramirez will likely be one of the best hitting catchers in the majors.

Corner Outfielders
Major League Average – 275/344/445/789; 32 2B, 4 3B, 20 HR
AAA Equivalent – 328/409/555/964; 42 2B, 5 3B, 28 HR, 112 K, 83 BB
AA Equivalent – 350/435/594/1029; 43 2B, 6 3B, 30 HR, 110 K, 90 BB

Near-Ready Rangers Prospect

Brandon Boggs – 257/362/463/825 (career minor league averages)
In 68 AAA at bats, Boggs’ 309/368/456/824 batting line was solid though probably not yet major league worthy.  As expected, his time in the major leagues was solid but unspectacular.  If Boggs is relegated to AAA in 2009, look for an improved slugging percentage to precede a mid-season call-up.    

Corner Infielders
Major League Average – 267/341/438/780; 30 2B, 2 3B, 19 HR
AAA Equivalent – 320/409/545/954; 41 2B, 3 3B, 28 HR, 87 BB, 110 K
AA Equivalent – 342/435/585/1020; 42 2B, 3 3B, 30 HR, 94 BB, 108 K

Near-Ready Rangers Prospect

Justin Smoak 
Smoak’s minor league resume is too sparse to predict what he should improve prior to a promotion to the big leagues.  Assuming he begins the year in Frisco, an OPS above 1000 would suggest that his time as a prospect will be short-lived.

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