Desmond Jennings: A Young Player Who Has Improved

As one of the writers of this site who helps cover the minor leagues, I find myself frequently visiting different statistical websites, trying to keep up with how the prospects are doing. Though I check the box scores every night for all the minor league teams, I find it helpful to occasionally take a step back and look at the full season numbers. More often than not, overall level of production by a player is surprising. Sometimes a certain hot or cold streak stays in my mind longer than it should, and it skews my overall view of how the player is performing.

Though I find Baseball Reference and Minor League Splits to be useful websites, my favorite venue for an overall look at a player's season is FanGraphs. For minor league players, its statistical breakdown is relatively simply; it shows the standard dashboard for players, just like the one used for major league players. The only notable absence is the lack of the value stats (Fld, BsR, and WAR). So for hitters, you still have the BB%, K%, ISO, BABIP wOBA, wRC+, and a collection of other stats.

When evaluating prospects, I feel that it is important to not just look at a player's triple slash line (batting average/ob-base percentage/slugging percentage. As player's get older and they advance through the minor leagues, I try to observe whether they are making improvements beyond the obvious. Let me use Ryan Brett, a prospect who has boosted his stock this year, as an example.

On the surface, it is easy to see Brett's improvements this year. His wRC+ is at 154, much higher than his 110 figure from last year. But when I look at Ryan Brett's improvements, I am more excited about the fact that his K% has dropped significantly (from 16.0% to 11.2%) and his ISO has gone up (from .107 to .139). A player moving up a level and hit for more power while actually lowering his strikeout rate is very impressive.

Sometimes, I feel like we forget that a player's development stops at the major leagues. While the Rays are notorious for holding their prospects in the minor leagues longer than most teams, these 22-25 year old players still have plenty to learn. Several weeks ago, there was a discussion on this site about the Rays failure to develop hitting prospects. One of the names brought up as an example of this was Desmond Jennings. Many had conceded that he was only a league average hitter, and that it was tough to consider a former top five prospect who became a league average hitter a success.

Oh how quick we were to ignore the possibility that a 26 year old Jennings had plenty of time and potential to make improvements. When looking at Desmond Jennings' statistics in the same way that I view prospects, the improvements are easy to see. Some observations:

- After striking out over 20% of the time in his first two seasons, Jennings is striking out only 18.4% of the time this season
- Jennings's 8.2% BB% from last year has climbed to 8.8%
- And while his peripherals have improved, he is also hitting for more power and hitting the ball with more authority -- his ISO has jumped from .143 last year to .177 this year; moreover, his BABIP is up by .010

While Jennings may never be the guy with a K/BB rate near 1 with good power like his 2009 minor league campaign gave us hope for, this season is a reminder that many of these young players are still making improvements. The Wil Myers we see today may only be a fraction of what he will be five years from now. The same can be said for Chris Archer. The young players that look bright for the Rays right now may only look brighter in the future.