Read all about the infamous “Merkle’s Boner” at SABR. Boner being an abbreviation for bonehead or a bonehead mistake–not, er, not that other thing. And Merkle clearly received a bad reputation for the entirety of his career because of this one fouled-up play. In fact, the notoriety seems wholly unjustified, as Merkle’s very own peers in The Glory of Their Times (1966) testify that many other deciding factors contributed to the 1908 Giants (Merkle’s team) losing the World Series to the Chicago Cubs.
Nothing can hurt you anymore, Fred. Sleep well and be at peace; you’ve earned your place among the cardboard men.