This stat is pretty compelling, if still not comprehensive.
It’s worth noting Nola’s lifetime numbers on four days rest and five days rest.
Four days — 23-22, 4.52 ERA in 56 starts.
Five days — 28-8, 2.60 ERA in 58 starts.
The thing is, that first pitcher is still probably worth having every four days over any of the other guys.
It's very old-school baseball, I don't think the numbers have ever favored pitching your ace on truly short rest in the playoffs either, but most managers still do it.