Split-season statistics can be misleading. It seems that major league players need only two bad Aprils in row to earn a reputation as a “slow starter” in some circles. In most of these cases, fans and analysts downplay the role random variation might have in explaining why a player might start strong or finish weakly two or three years in a row.
The minor leagues are designed to be educational, however, so split-season statistics among young minor leaguers might be a leading indicator of development. For example, current Rookie of the Year candidate Ryan Braun was among the top second-half performers after a modest first half performance in 2006.
Analysis of split seasons doesn’t always have predictive value for developing ballplayers, of course. I recently predicted a breakout season for Van Pope partly because of his strong second-half performance in 2006. While Pope is better than his .221 average might lead you to believe, he still isn’t having anything resembling a breakout season this year.
With that caveat in mind, it can still be fun to look at the top performers and speculate on what this means for their future. I will list the top 15 second-half performances in the minor leagues by players under 24 and rank them by wOBA. This statistic, featured prominently in The Book, is a run value estimate that is scaled to look like on-base percentage. Strikeout percentsage, walk percentage and isolated power (slugging-batting average) are also listed for each hitter:
Top Under-24 Minor Leaguers Since June 15 Org Name Age Level PA K% BB% ISOP wOBA TEX Chris Davis 21 A+/AA 221 26.2% 7.2% .373 .474 TB Ryan Royster 21 A 226 25.7% 7.1% .314 .453 TEX John Mayberry 23 A+/AA 199 23.6% 6.0% .269 .435 TEX Mauro Gomez 22 A 218 22.9% 4.1% .277 .435 CLE Matt Whitney 23 A/A+ 217 21.1% 8.3% .255 .431 CLE Josh Rodriguez 22 A+ 239 18.4% 8.8% .231 .421 LA Lucas May 22 A+ 213 23.0% 4.2% .221 .421 WAS Francisco Plasencia 23 A/A+ 232 18.5% 10.8% .244 .420 CIN Jay Bruce 20 A+/AA/AAA 231 25.1% 8.7% .271 .420 SD Matt Antonelli 23 A+/AA 244 14.3% 13.9% .226 .418 COL Chris Nelson 21 A+ 255 12.9% 11.8% .277 .410 BOS Jon Still 22 A+ 248 15.7% 23.0% .250 .407 CHC Brian Dopirak 23 A+ 219 22.8% 8.2% .229 .406 LA Anthony Hatch 23 A+ 207 16.4% 5.3% .226 .406 BOS Jed Lowrie 23 AA/AAA 266 17.7% 10.2% .252 .401
Here are notes on some of these prospects:
Texas Rangers | 3B | 22 years old
The bad news is that Davis’ all-or-nothing approach prevents him from becoming an above-average on-base threat. Also, much of his power occurred at his hitter-friendly Bakersfield of the California League. On the other hand, he is hitting everywhere. Davis already has slugged eight home runs since a promotion to Double-A Frisco earlier this month. Perhaps most importantly, Davis’ breakout season has occurred while he moved across the infield from first base to third base. That kind of flexibility should keep him from stalling at Triple-A for the next few years.
Texas Rangers | RF | 23 years old
The Rangers’ patience with Mayberry is finally starting to pay off. He isn’t a well-rounded hitter yet, but he also isn’t striking out any more often than he was at a lower level last year and his raw power has translated to 30 home runs this year.
Cleveland Indians | 1B | 23 years old
The highly-touted prospect from the 2002 draft class has survived a series of surgeries since breaking his leg in the spring following his professional debut. He was finally healthy enough to play third base in the Carolina League last year, when he demonstrated modest power while striking out in one of every three plate appearances. He began 2007 in Single-A, earned a promotion in June, and has continued to hit the ball hard all year. His discipline has worsened throughout the year and he is striking out four times for every walk he has earned in August. Whiteney has also moved into a first base/designated hitter role, so he’ll need to keep up this pace to contend for a major league role in another year or two.
Cleveland Indians | SS | 22 years old
Rodriguez was considered among the top NCAA infield prospects just a few years ago, but his professional career had been modest until a few months ago. Rodriguez had the worst first half among all the players in this list, so the jump in performance from April to August might be the most extreme among all prospects in baseball this year.
Cincinnati Reds | OF | 20 years old
Not much to say here. He’s probably the best prospect still playing in the minor leagues. I do worry that, as I predicted with Alex Gordon last year, Bruce won’t have the smoothest transition to the major leagues next year due to his inconsistent ability to make contact.
San Diego Padres | 2B | 22 years old
Antonelli earned a $1.5M bonus last year because of his exceptional athelticism and polished plate approach, but his power potential was unknown. The 22-year-old transitioned from third base to second base this year and, along the way, he learned to load his hands and hit for some power. The following chart plots 15-day averages in isolated power over the course of Antonelli’s career:
Antonelli would be a solid prospect at third base. At second base, he’s a great one.
Colorado Rockies | SS | 21 years old
The ninth overall pick of the 2004 draft continues to develop slowly into the player the Rockies imagined he would be. Nelson made some notable improvements in the first half of the 2007 season when he walked and made contact more often than ever before. In July, he slugged nine home runs. Before then, Nelson had never hit more than three in a month.
Boston Red Sox | 1B | 22 years old
That’s not a typo in the table above; Jon Still really has walked in 23% of his plate appearances since mid-June. Among full-time minor leaguers, only Taylor Teagrden has walked more frequently than Still this year. He could finish his season particularly strong now that he’s playing half his games in a windy, fly-ball-friendly home stadium.
Boston Red Sox | SS | 23 years old
Lowrie might be the most underhyped prospect playing for a big-market baseball franchise. He struggled with an ankle injury in 2006 and fell under the radar of most fans as fellow 2005 draftees Jacoby Ellsbury and Clay Buchholz emerged as top prospects. In 2007, Lowrie has remained healthy while holding his own at shortstop and demonstrating solid on-base skills and above-average power for a middle infielder.