Drafting in the top six picks for the fourth time in the six year tenure of general manager Jack Zdurencik, the Mariners appeared that they may be on the outside looking in with a fairly clear cut top five players in this class and the sixth pick overall. However, when the Cubs took Kyle Schwarber with the 4th pick, the Mariners knew that at least one of those five would be available to them. The Mariners ended up taking Jackson, who came into the season viewed as the top high school hitter according to Baseball America.
A graduate of Rancho Bernardo High School in San Diego, Jackson finished up his prep career with a .379/.513/.844 slash line and 47 home runs in his four years on varsity. While he played catcher primarily in high school, the Mariners announced when he was drafted that he would be moving to the outfield, which was expected for nearly any team interested in drafting him. He signed quickly with the Mariners to a bonus worth $4.2 million before heading out to the Arizona Rookie League. A liner to the face caused him to miss a month, but did return for a few games before the end of the season. Overall, he finished the year with a .274/.337/.464 slash line with two home runs, 16 RBI, nine walks and 26 strikeouts in 84 at bats.
The reports on Jackson all point to his potential to be the best hitter to come out of the 2014 draft class. He has above-average to plus power potential, capable of hitting 25-30+ home runs on a regular basis. The power doesn't come necessarily with a drop in batting average, as his ability to hit is expected to turn into decent batting averages (.270-.280 potentially?) down the line. He's not likely to help out much with stolen bases, but could provide a token few some years.
There was the potential that Jackson could have kept going as a catcher defensively, and that he would have been at least reasonably good behind the plate. However, the Mariners have chosen to go with a similar development path that former top prospects Bryce Harper and Wil Myers went, specifically moving Jackson to a position lower on the defensive spectrum in order to move his bat through the system more quickly. He should turn into at least an average defender in one of the corner outfield spots, although his bat is good enough that a move to first base or even DH might not totally destroy his prospect value.
His bat is considered advanced enough that he could move quickly through the lower minors, although I wouldn't expect to see Jackson in the majors until at least 2017 at the soonest. Once there, even with the potential for Seattle to drag his offensive numbers down somewhat, Jackson should still be capable of .270-.280 batting averages most years, with lots of doubles and 25+ home runs on a consistent basis. He will likely be one of the top targets in most minor league drafts this year, and should be as he is capable of being a top 25 outfielder on the low end with the potential for some seasons of 30+ home runs as well.