If you give guys days off over several days, you reduce your chances to win on each of those days. If you have them all rest at once, you only reduced your chances to win one game, and it's a game you had a strong chance to lose anyway, even if they all started. I understand that, but by taking 1 guy out of a lineup isnt going to reduce your chances of winning that much. Doing it on a day with your number 5 starter is on the mound facing 1 of the best pitchers in the game, you are basically forfeiting. If you take 1 guy out when you have say Demp, Harden, and Lilly, on the mound your chances arent reduced much at all. You are most likely going to lose a their ace vs your 5 matchup anyway. I don't think there is an ideal way to get guys rest. But it's day after night, lots of guys are banged up, it's "getaway day", they aren't playing a division opponent. It's one game out of 162.