If I put a guy on the bench but he takes a PH AB in the 9th does he fatigue at say 1/4th the rate he would if he played the whole game or is it basically all or nothing? Just wondering if it's worth benching starters occasionally to rest em but if I can get away with just leaving them available to pinch hit or if I need to all the way rest them to get that affect.

not 100% certain on this but i believe it is a combination of plate appearances and innings played in the field.

not sure which one weighs heavier. but if it's 50/50 then a PH AB will be closer to 1/8 fatigue if he's not spending any time as a fielder.

Recently asked a similar question. I had a C in the minors that I want to get into as many games as I can. Problem is his Durability is like 65 so he gets to the low 90% pretty quick. So I benched him against RHP but had him as the #1 C coming off the bench. Guy played in 8 straight games with just 1 AB per game but his % went up 3% over that 8 games.

Thanks Tire! That's great info.