I would like to know this myself.
I want Demarco Murray to get the bulk of the carries, say, 50%; 40% for Ryan Mathews; 10% for Darren Sproles.
Today I played with the RB sub OUT/IN sliders, set OUT=77, IN=90. Playing against Green Bay on All-Pro difficulty 12-min quarters, I ran the ball
to death. Ran Murray like 28 times for 113 yards; Mathews for like 21 times for 140+ yards (he broke a 92-yard run); and Sproles like 7 times for 40+ yards. Towards the end of the game my 4th string RB Kenjon Barner ran like 4 carries.
Overall I liked the way carries were split. However, there were times in the 4th quarter where Murray was nowhere to be seen. I ran him like 25 times through 3 quarters.
To my knowledge he was not run down stamina-wise, although, how do you find this information, his energy levels? I just wonder, if the game was on the line (I was only up 24-12 in the 4th Q), would the game have re-inserted my primary back Murray back into the game??????