1ST PLACE (blue) denotes the score achieved by the player who had the highest score for that mech.
TOP 50 AVG (red) denotes the average score among the top 50 players for that mech.
50TH PLACE (orange) denotes the score achieved by the player who had the 50th highest score for that mech (at the bottom of the leaderboard).
The mechs are sorted in ascending order based on the average scores of the top 50 players of each mech. The 1st Place scores indicate a potential ceiling for the max performance that can be wrought from the mech.
These scores must be taken with a grain of salt, of course. Player population varies for each mech, so the chart cannot be taken as an absolute measurement of the mechs' relative strengths. That said, it is a good general indicator of how one Hero mech compares to another.
And here's another chart that sprinkles in the mechs from the recent Founder and Resistance tournaments along with the Heroes.
Edited by Crotch RockIt, 30 June 2015 - 05:05 PM.