Top 50 MLB prospects update

Byron Buxton moves to top spot; No. 1 draft pick Mark Appel in top 10

Updated: July 18, 2013, 5:25 PM ET
By Keith Law | ESPN Insider

Byron BuxtonAP Photo/Kathy WillensByron Buxton had scouts and fans buzzing at the Futures Game.

At the MLB season's midpoint, just past the signing deadline for drafted players, here is a fresh look at the top 50 prospects still in the minor leagues, including a new name on top.

These rankings are based primarily on upside or ceiling, not on proximity to the majors, so the list includes a mixture of players as high as Double-A or Triple-A and a few who have signed but either have yet to make their professional debuts or who have just a few appearances in the low minors.

Players who have already passed the cutoff for Rookie of the Year eligibility are ineligible, as is anyone currently on a major league roster.

Note: I use the 20-80 grading scale in these comments to avoid overuse of the terms "average" and "above average" across the player comments. On that scale, a grade of 50 equals major league average, 55 is above average, 60 is plus, 45 is fringe or below average and so on.

1. Byron Buxton, CF | Minnesota Twins (age 19)
Current level: High Class A (Fort Myers)
Preseason ranking: 22

I've been a Buxton fan for a while and thought he was the best talent in the 2012 draft, although even I'm a little uncomfortable with the extent of the hype around him right now.

To see Keith Law's complete rankings and analysis of the top 50 prospects in MLB, become an Insider today.