The Rangers might have more quality relief prospects in the upper minors than any team in baseball. Alexi Ogando, Pedro Strop, Omar Beltre, Guillermo Moscoso, Zach Phillips, Josh Lueke, and Warner Madrigal all feature 90-plus mph fastballs and at least one above-average secondary pitch.
Add Tanner Scheppers and Michael Kirkman to the list and the organization currently has nine pitchers at Double-A Frisco and Triple-A Oklahoma City with the combination of stuff and performance to be quality major league relievers.
2010 Performances of a Few Rangers Pitching Prospects
Moscoso, Ogando, and Kirkman have been slightly prone to fly balls. Beltre and Kirkman have struggled with their control. Beyond that, there's not much to complain about and a whole lot to be excited by. Noteworthy are Strop's significant improvement in walk rate (2.6 BB/9 in 2010 vs. 4.9 BB/9 in 2007-2009), Phillips' uptick in strikeouts (11.0 K/9 in 2010 vs. 8.7 prior to 2010), and Scheppers' and Ogando's dominant debuts.
Five of the pitchers (Strop, Ogando, Beltre, Lueke, and Madrigal) feature the same three-pitch mix -- four-seam fastball, slider, split-finger fastball. A look at Pitch f/x data from last season reveals that there were ten major league relievers who tossed at least 40 innings using a fastball/slider/splitter combo (see table below). Four of the ten were closers and six of the ten were among their team's most valuable relievers. As expected, there is a strong correlation between fastball value and performance and the most effective relievers on the list combined a good fastball with at least one aboveaverage secondary pitch. The least effective relievers on the list struggled with control.
Available Pitch f/x data and scouting reports indicate that the pitch velocities recorded by the Rangers' relief prospects are indistinguishable from the major league relievers. The fastball velocities of the Rangers' three hardest throwers -- Ogando, Strop, and Lueke -- rank alongside the major league closers on this list.
Fastball/Slider/Splitter Relievers -- Majors vs. Rangers' Prospects
Explanation of Table
Pitch velocities and values for major league relievers are from FanGraphs from 2009. Velocities are in MPH. Values are as follows:
● ++ = >1.00 win/100 pitches
● + = 0.10 to 1.00 wins/100 pitches
● 0 = -0.10 to 0.10 wins/100 pitches
● - = -1.00 to -0.10 wins/100 pitches
● -- = < -1.00 wins/100 pitches
[Strop's and Madrigal's pitch velocities are from major league Pitch f/x data. Ogando's pitch velocities are from 2010 spring training Pitch f/x data. Lueke's and Beltre's velocities are from scouting reports by Jason Parks and Jason Cole.]
Because command, consistency, pitch movement, mound presence, and pitch deception are significant factors in determining pitch value, it is unclear whether the Rangers' prospects will enjoy the same level of success as the major league pitchers. It is worth noting, however, that the 2010 minor league performances of the Rangers' pitchers (table above) are similar to the Double-A and Triple-A numbers posted by the present-day major league relievers (table below).
Intriguingly, the AA/AAA stats of the major league relievers are very consistent with what they have posted in the major leagues. While there is certainly a selection bias at play here, it seems likely that several of the Rangers' minor league relievers will soon be making significant contributions out of the major league bullpen.
Career Minor and Major League Stats of Major League Relievers
[* -- Starting pitcher in AA/AAA; reliever in major leagues. # -- Major league numbers are pre-injury only.]