Minor League Breakdown: The Hitting Prospects

Overall state of the farm

Nearly a month has gone by since my last minor league breakdown of the hitting prospects. Since then, the Rays MiL pitching has gone backwards again. The Durham Bulls, the Montgomery Biscuits AND the Charlotte Stone Crabs are last in pitching in their respective leagues. Only the Hot Rods have an above average pitching staff (2nd). On the hitting side, not much has changed, though. The Hot Rods moved into 1st place according to OPS, though, which is a result of a very balanced offense - led by Josh Sale and Jeff Malm.
 

OPS-CH and ERA-CH stands for the OPS and ERA change since the last minor league breakdown.

Prospects stats overview

Today I'm going to talk a bit about specific warning signs to look out for when trying to evaluate whether a hitter's offensive performance is sustainable or whether a hitter can make it in higher levels. An excellent indicator for the latter (success at higher levels) is the strikeout-rate (K%). Only a very limited number of elite hitting prospects is able to be successful at the major league level with a high level of strikeouts in the minors (e.g.: Ryan Howard, Giancarlo Stanton). More often than not, though, players with high strikeout numbers falter at the major league level (e.g.: Brandon Wood, Kila Ka'aihue, Travis Snider, Jeff Clement, ...). Especially the combination of a low batting average AND a high strikeout rate most of the time is deadly for a hitter. Therefore, especially Kyeong Kang (28,4 K%, .247 AVG) and Tyler Goeddel (28 K%, .250 AVG) have such warning signs. Power hitters like Henry Wrigley or Jeff Malm also have to be cautious, not to make insufficient contact. 
Here is the data:

(click on the image for a better view)

Prospects on the rise

1. Ryan Brett ... While having been solid all season long, he is tearing it up as of late. Better plate discipline (increased BB%) and some power showing have resulted in a .451 wOBA and .937 OPS over the last 75 PA's. He also has been stealing much more bases since the start of May (17) than in April (only 2).
2. Stephen Vogt ... After heavily struggling over the first one and a half month of the season, Stephen Vogt has found his rhythm. A .450 wOBA and .983 OPS over the last 56 PA's are excellent. Lets let him settle for one more month in AAA, and then try him at the major league level again.
3. Todd Glaesmann ... I was very much looking forward to his performance this year, as he was excellent in Australia in the off-season and as he repeats the league. Unfortunately, it took him until mid-May to show the promise I was hoping for. Since then, he has been very solid, though (92 PA's, .908 OPS, .408 wOBA).
4. Jake Hager ... I'm really pleased by the progress of Jake Hager. Higher BB% (3.2% by 5/21/12 and 5.5% now), lower K% (11.9%  vs. 11.4%), higher OPS (.496 --> .652) and wOBA (.225 --> .293), higher ISO (0.051 --> .104) and a higher Speed factor (2.7 --> 3.7). The last month has been a very good one for him (.409 wOBA, .914 OPS).

Prospects to be falling

1. Reid Brignac ... Falling, and falling, and falling, and falling, ... . Only the solid walk rate of 10.7% can be seen as a positive with him.
2. Brett Nommensen ... While having been injured for lots of the time, he hasn't shown anything in the contact and power department as of yet. Still a very small sample size, though.
3. Riccio Torrez ... He was considered a low upside pick when being drafted and his performance so far hasn't done anything in order to increase the expectations. A .400 OPS and .202 wOBA in his last 73 PA's and a wOBA below .300 on the season are not doing his prospect status any favour.
4. Cole Figueroa ... After excellent performances in Montgomery, he is cooling off as of late in Durham. Can he take this hurdle and perform in AAA as well or did the Rays know what they were doing when they sent him back to AA at the start of the season?

Glossary

All of the stats provided above are excluding the stats from the previous day. I preferrably use FanGraphs as source for the stats. Click on each stat for its explanation:

• Traditional stats: AVG, OBP, OPS, BB% and K%.
• Newer stats: ISO, wOBA, wRAA, BABIP and Spd.