Jackson was ranked by some as the Cubs' number one prospect this preseason. Baseball America had him ranked as the 38th best prospect in baseball.
Spending most of his time between high-A and double-A last season, Jackson hit a combined .297/.395/.493 with 12 home runs and 30 stolen bases. Through 152 plate appearances at double-A this season, he has hit .266/.391/.468. His overall line at double-A from 2010 and this season is .272/.375/.463 with 10 home runs and 31 stolen bases in 425 plate appearances.
Clearly, Jackson knows how to draw a walk. His OBP this season is still a terrific .391 despite the low .266 AVG. However, that doesn't mean much unless you're in a league that uses OBP instead of AVG. While the 15 home run power and 30-plus stolen base potential is certainly there, the strikeout numbers are quite concerning. Jackson has struck out 36 times this season for a strikeout rate of 29 percent. His minor league career strikeout rate is about 26 percent and his strikeout rate at double-A (2010 and 2011) is about 28 percent. The high strikeout rates cause me to question how effective Jackson will be against big-league pitching, especially considering he'd be skipping triple-A should he get the call to the big-leagues right now.
If Jackson struggles with his strikeouts at this big-league level, his OBP probably won't be high enough to let his stolen base potential shine. He just returned from a hand injury, so that could impact his swing as well.
Long-term, Jackson looks like a guy that could be a mid-level fantasy outfielder, capable of .270/.370/.460, 15/30 HR/SB seasons (much more value in OBP leagues). However, at 22 years of age and with no experience above double-A (and too many strikeout at double-A), I'd have to put his potential fantasy impact in 2011 at a very minimal level.