Is A-Rod the new Mr. Autumn?

A bit of postseason trivia, via my friend Allen Barra: Alex Rodriguez has now played in 42 postseason games. In those 42 games, he's batted .291 with nine home runs and 25 RBI.
Rodriguez In Reggie Jackson's first 42 postseason games, he batted .265 with seven home runs and 19 RBI. Through 42 games, Reggie Jackson was just another great player who hadn't done anything particularly special in October. So, how did get that nickname? Barra:

    What changed everyone's perception was Reggie's 43rd postseason game, Game Six of the 1977 World Series against the Los Angeles Dodgers, when he hit three home runs. No one called him "Mr. October" before that game. Next time, think about this before you start to dump on any player for choking in the postseason. What a difference one game can make.

Has anyone traced the beginnings and the popularization of the "Mr. October" nickname? I'm not sure if one game would have been enough, all by itself, to get "Mr. October" onto Reggie's Hall of Fame plaque. But the very next October, he drove in 14 runs: six in just four games against the Royals, and then eight in six games against the Dodgers. That was the same World Series in which Jackson leaned into a relay throw from Bill Russell, resulting in a Yankee run that proved crucial.
For two straight Octobers, then, Reggie Jackson took center stage. And that's why "Mr. October" stuck, I think.

All of which is ancient history, of course. Barra's larger point is that Rodriguez has done perfectly well in the postseason. Even if he hadn't, that wouldn't necessarily tell us anything about his character or his abilities, any more than Willie Mays' .337 postseason slugging percentage or Jeff Bagwell's .226 postseason batting average tells us anything about theirs.

Neither Mays nor Bagwell had a great number of chances. But if you give a great enough chances, eventually he's going to hurt you. Just ask the Minnesota Twins.