I think the opener has been around forever. Back in the day the talent pool was such that No team had 5 quality starters. Every pitcher knew that when the 3-4-5 starters were up it was All Hands on Deck. This is not new. For the Rays(or anyone else) taking credit for a new innovative way of managing their pitching staff is just Nonsense. They dreamed it up from reading history books. The best teams still go 5 starters deep and what you do that 4-5th day either makes or breaks you.
Maybe but nobody else was reading those history books for two or three decades.