April is probably my favorite part of the baseball season because it is the month when one usually sees the most dramatic improvements in individual players.  The first month of the season is often when you see whether the six months of work that a player put in during the off-season is paying off with improved performance.  But distinguishing real improvements from hot starts can be tricky.

After the first month of the 2008 minor league season, Jose Vallejo had hit 333/379/500/879 in teh Cal League after posting an OPS of 578 in 2006 and 646 in 2007.  One level down, Kennil Gomez had completed an equally impressive first month with a 3.06 FIP, 23 K's, and 2 BB's in 29.2 innings.  Gomez' teammate, Ian Gac, was the most feared hitter in the MWL with a line of 395/485/802/1287.  The highly touted Cristian Santana was also off to a very good start as an 18 yo in his first year of full season ball with a line of 274/349/466/815.  On May 1, 2008, all four players looked to be among the twenty best prospects in the Rangers minor league system.

Vallejo was promoted to AA and finished the 2008 season with a 292/345/415/760 line, cementing a spot among the Rangers' Top20 prospects.  If not for an injury, Gomez might have also received an in-season promotion and ended the year as one of the Ranger's minor league Top20.  Gac was promoted to the Cal League where he was exposed as a non-prospect (257/311/449/760).  Perhaps the most disappointing player in the Rangers' system in 2008, Santana finished as a 232/298/398/696 hitter.

In retrospect, Santana's obscene K-rate (32 strikeouts in 73 April AB's) and unsustainable BABIP (.447) were harbingers of the pain that he and his fans were going to experience.  Gac's April 2008 numbers failed to reveal any areas of weakness, but his previous three seasons in the Rangers system (720 OPS in Clinton in 2005, 599 OPS in Clinton/Bakersfield in 2006, and a demotion to Spokane in 2007) suggested that April 2008 was merely a case of a veteran A-baller taking advantage of a bunch of 1st and 2nd year players.

Given the benefit of experience and the incredible statistical resources provided by Minor League Splits (www.minorleaguesplits.com), below are predictions of which Rangers fringe prospects are making their ways into the Rangers' Top 20 and which ones are simply setting us up for the coming heartbreak.

Breakouts

Manny Pina - Pina finished April 2008 as a 481/518/731/1249 hitter.  Pina benefited from a .537 BABIP that is clearly unsustainable, though the high average appears to be the result of an obscenely high line drive rate (41%) that is more than two-fold higher than the Texas League average.  Interestingly, Pina's line drive rate improved throughout his 2008 season (from 12% in April to 24% in August) which suggests that his ability to recognize and square up pitches is improving and perhaps he can maintain a LD% (and corresponding BABIP) that is above league average.  Pina is also showing annual increases in extra base hits, with 12 in 2007, 21 in 2008, and 35 projected for 2009. Assuming Pina's BABIP drops to ~.325, he is likely to post a hitting line in the neighborhood of 300/350/450/800 as a 21 yr old in AA and add his name to the list of catchers that experts discuss when addressing Texas' catching depth. 

Mitch Moreland - Though slightly less talented than in years past, the Cal League nonetheless features 8-10 legitimate hitting prospects.  Among these prospects, only Buster Posey has better numbers than Moreland's 325/394/578/972.  Like last year when he ranked among the Midwest League leaders in almost every major offensive category, Moreland is walking almost as often as he strikes out and getting extra base hits almost as often as he singles.  When he is promoted to Frisco, expect Moreland's advanced hitting approach to translate well to the Texas League and allow him to experience the same successful transition to AA that Boggs, Duran, Borbon, Vallejo, Pina, Whittleman, and Tracy have enjoyed in recent years.   

Mike Bianucci - Bianucci is to the SAL in 2009 as Gac was to the MWL in 2008.  But unlike the former Lumberkings star, Bianucci's numbers this year (373/435/680/1115) are largely indistinguishable from his numbers last year (316/386/535/921).  Assuming he is promoted to Bakersfield and continues to hit as he has done in the SAL, Bianucci should be the best hitter on the Blaze with a SAL to CAL translated line of 358/419/665/1084.  Those would be outrageous numbers even for a 23 yo in High A. 

Heartbreaks

Richard Bleier - Bleier's 1.14 ERA is second only to Wilfredo Boscan among Hickory's starting pitchers.  In 23.2 IP this year, Bleier has GO/AO that is greater than 2 and a BB/9 that is less than 2.  And then there are the two numbers that reveal Bleier as the heartbreaker that he is: 6.2 and 22.  The former is Bleier's K/9 which is at least 3 less than it should be for a legitimate prospect, especially considering the fact that the second number is Bleier's age, which places him among the elder statesmen of the SAL.  Bleier aspires to be Jared Hyatt, and while the two pitchers are probably a lot of fun to be around, neither is likely to be a guest of honor at a prospect party.

Jake Brigham - In 18 April innings, Brigham has struck out 18, walked 6, and given up 4 earned runs.  Brigham's peripherals thus far in 2009 are in-line with his career numbers (~9 K/9, ~3BB/9, ~1.25 WHIP), thus it seems likely that he can at least maintain his early season success so long as he remains in Hickory.  Because he is 21 years old, Brigham will likely be promoted to Bakersfield as soon as the Rangers are confident that his elbow is sound.  Unfortunately, Blaze pitchers all share a room at the Heartbreak Hotel so you should expect Brigham's early season success on the east coast to be forgotten in a barrage of extra base hits and earned runs on the west coast.  Hopefully by this time next year, Brigham (along with Main, Beavan, Gomez, and Murphy) will be experiencing the same career renaissance that Kasey Kiker is enjoying this year.  

Michael Kirkman - In a rotation featuring four prospects (Michael Main, Blake Beavan, Tim Murphy, and Kennil Gomez), Kirkman is the one Bakersfield starter who has not faltered out of the gate.  After walking nearly a batter per inning in a little less than 60 innings in 2006 and 2007, Kirkman's 21 yo season last year must have been a huge relief for the LHP as he dropped his walk rate to less than 3BB/9 and his WHIP from greater than 2.0 to less than 1.3.  In 24 innings this year, Kirkman has struck out more than a hitter per inning while posting a 2.89 ERA.  Unfortunately, Kirkman's walk-rate appears to be creeping up (>4BB/9) and his .148 BAA with runners in scoring position is more than 100 points lower than his BAA in all other situations.  Although Kirkman's progress the last 1+ seasons is encouraging, his days with a sub-3.00 (or even sub-4.00) ERA are numbered.  By the end of the season, you can expect the Rangers' minor league gurus to be discussing whether Kirkman might have the same type of bullpen success that Zach Phillips is enjoying this year.

Tim Smith - Smith has gotten better as he has advanced - 277/388/373/761 in Spokane/Clinton in 2007, 297/356/448/804 in Clinton in 2008, and 351/422/509/931 in Bakersfield thus far in 2009.  Unfortunately, Smith's AVG and SLG in 2009 have benefited from a 429 BABIP despite a line drive rate that is below 10%.  Unless he is able to increase his homerun rate (<4%) or decrease his strikeout rate (>20%), Smith's Bakersfield stats are likely to slip into the 290/360/440/800 range that is reserved for 23 yo non-prospects in the Cal League.