Recently a friend mentioned that the Yankee winning percentage with Derek Jeter playing was the same as without Derek Jeter playing. This prompted me to consider that there might be such a thing as Wins Above Derek Jeter: WADJ, pronounced the way it's spelled for the comic effect.
For the Yankees to improve they need to replace Jeter with a player who has WADJ.
Many years ago Bill Deane manually researched the runs allowed by the Yankees with and without Joe DiMaggio in center field: it was about the same.
The WADJ guy has also told me that the Yankee record in save situations in the 1950s was about the same as during the Mariano Rivera era. Between bookend relief specialists Joe Page (1949-1950) and Ryne Duren (1958-1960) Yankee manager Casey Stengel used a different pitcher the most in relief each season and none of them were household names.
June 5, 1963 in Baltimore Mickey Mantle broke his foot trying to catch a Brooks Robinson home run in a 4-3 Yankee win and did not play again until he pinch hit a home run against Baltimore at Yankee Stadium in an 11-10 win. During his absence and despite losing the first three games the Yankees record was 40-20 (.666). Before Mantle's injury the Yankees record was 27-18 (.600). For the season the Yankees were 104-58 (.642).
The Rivera anecdote just confirms that the closer role is vastly overrated. And maybe DiMaggio's defense is also overrated. But the main lesson is that baseball is way too dominated by pitching. Even great players can be marginalized.