The League Pool is $3,460,000 Per Club. The system calculates the amount of playing time vs the player's salary for that season. Usually backups and players making the minimum that assume a large chunk of playing time rack up the big numbers.
The amounts do not count against the salary cap and are not to be paid until 4/1/2016.
From Aaron WIlson of the Baltimore Sun:
The fund was created in 2002 under the collective bargaining agreement to supplement player compensation.Below is a list of Giants who eclipsed 100K or more in Performance Based Pay for 2013:
The money is computed through an index based on a players' regular-season playing time, fully salary, prorated portion of signing bonus and earned incentives compared against other players on the roster to figure out how much they should be paid.
S Will Hill $215,375.65
OL Kevin Boothe $207,602.85
LB Spencer Paysinger $193,841.08
S Ryan Mundy $163,963.86
LB Jacquian Williams $157,306.38
CB Trumaine McBride $133,680.32
C Jim Cordle $115,089.15
LB Mark Herzlich $114,166.86
WR Rueben Randle $107,809.25