Hader's multi inning ability makes it different though as you don't always know how long he'll be able to go. So if you bring him in planning for 2-3 innings to 'close' at the end. but then the pitch count gets high and you've already used the others (Knebel, Jeffress) then you're left with who knows what to finish it. So if you keep holding him to pitch 1 inning or maybe the last out or two of the 8th if lefties then you'll end up lowering his innings. Also, his multi inning usage makes him unavailable for days at a time, thus creating more variables. Personally I like what they did to start the year when Knebel was down, just go with who ever is fresh and based on matchups. Forget that Save is even a stat. Also, his left handedness is a factor. you want to use him when the pile of lefties are up in a lineup to maximize his value, and you can't predict when that will be in a game. Also, if you bring him in earlier in the game and the other team then yanks all their lefties it provides Knebel/Jeffress an advantage later in that the lefties are out.