John Sickels, over at Minor League Ball, has been ranking the top prospects in each system. While not a grade of the entire system, one would think the top 20-25 prospects for each system are a good indicator of the entire system's grade. Here are the gauges he uses:

"Grade A prospects are the elite. They have a good chance of becoming stars or superstars. Almost all Grade A prospects develop into major league regulars, if injuries or other problems don't intervene. Note that is a major "if" in some cases.

Grade B prospects have a good chance to enjoy successful careers. Some will develop into stars, some will not. Most end up spending several years in the majors, at the very least in a marginal role.

Grade C prospects are the most common type. These are guys who have something positive going for them, but who may have a question mark or three, or who are just too far away from the majors to get an accurate feel for. A few Grade C guys, especially at the lower levels, do develop into stars. Many end up as role players or bench guys. Some don't make it at all."

Here are his results through 15 teams:

A- or higher
Diamondbacks 4
Mariners 2
Royals 2
Orioles 2
Rays 1
Cardinals 1
Braves 1
Rangers 1
Tigers 1
B+ or higher
Blue Jays 8
Cardinals 5
Diamondbacks 4
Braves 4
Royals 4
Mariners 3
Orioles 2
Rays 2
Phillies 2
Tigers 2
Astros 2
Rangers 2
Twins 1
Dodgers 1
B or higher
Cardinals 11
Blue Jays 9
Rangers 9
Royals 7
Rays 6
Braves 6
Diamondbacks 5
Mariners 5
Tigers 5
Twins 4
Brewers 4
Dodgers 4
Orioles 3
Phillies 2
Astros 2
B- or higher
Blue Jays 17
Rangers 16
Braves 16
Rays 14
Cardinals 13
Royals 13
Twins 13
Diamondbacks 12
Mariners 11
Dodgers 10
Brewers 9
Phillies 8
Orioles 7
Tigers 6
Astros 5

These don't necessarily speak for John's overall grades for the organizations, and I don't even know if he ranks entire orgs, or just sticks to the player level. But it appears he will have the Astros in the bottom 5 clubs in the league. How scary would this be without the Pence and Bourn trades?