HAL's tendencies re: relief pitchers...

does HAL favor the endurance rating (R2 vs. R3) or the IP (87 vs. 60) when making a decision?...I know these things are a factor, but I've yet to figure out how HAL's brain works...I've got 2005 Kevin Gregg (RH, R2, 87IP) and H. Ramirez (LH, R3, 60IP), and I'm wondering who will get the innings, since Ramirez has the better endurance rating but pitched less innings...