What is a true "innings eater"?

I keep hearing Mike Pelfrey spoken of as an "innings eater" because he provides 200 + innings per year.

Should 200+ innings per year be our definition ?

The title carries with it a certain level of "positiveness", so I have been wrestling with our current definition.

I also remember in the "pre pitch-count days", that it was normal for a SP to log 180+ innings, and there were many guys who regularly went over 225 IP per year. Back then, it was normal for a rotation to have 3 SP with over 180 IP per year. An "innings eater" (based upon innings pitched) back then would have been 270-300 IP.

What I guess I'm really getting at, is that I don't see Pelfrey's career overall as being quite so positive. Yes, he stays off the DL. Yes, he gives us 200 IP...... BUT.... how many games does he really preserve our bullpen? Does he often pitch 7+ innings ? (At least last year wasn't the case.) What benefit is there to one pitcher taking the ball every 5th day and giving us 5 2/3 to 6 mediocre innings per game against a couple of other approximately .1 WAR pitchers sharing the #5 rotation spot and doing the same? Either way, our bullpen gets used early in the game.

My goal isn't to pick on Pelf, just to point out that his "type" of "innings eater" doesn't necessarily benefit a team significantly. Perhaps this positive type of moniker should go to someone who preserves the bullpen a bit more.

Thoughts?