Mister scotch, that "old saying" originated from something Dodgers manager Leo Durocher said to Dodgers broadcaster Red Barber. On July 5, 1946, the Dodgers were in first place in the National League. The Giants were in last place. They had split a doubleheader the day before. In his book Mel Ott: The Little Giant Of Baseball, Fred Stein quoted Barber telling Durocher, "Your guys were lucky to split yesterday the way the Giants were hitting, especially those home runs.” Durocher scoffed, “Hell, they were nothing, just cheap Polo Grounds specials.” Barber said, “Come on, Leo, be a nice guy and give credit where it’s due.” Durocher said, “Nice guys! Do you know a nicer guy than Mel Ott? Or any of the other Giants? And where are they? The nice guys over there are in last place!”
Durocher made two observations: the Giants are "nice guys" and they're "in last place." Somehow his observations merged into the saying "Nice guys finish last," something he never meant to imply. And, as I often say, almost everything reminds me of a song.