Research for my next book, about the OaklandA’s dynasty of the 1970s, to be published by Houghton Mifflin in 2015, has turned up boundless examples of unwritten rules from that bygone era. On-field revenge was more institutionally prevalent then than it is now, leading some players to go to extremes. This tale of getting things done properly is brought to you via the Oakland Tribune, May 22, 1972:

[A’s pitcher] Ken Holtzman was sailing along with a 2-0 lead in the second inning when he grounded to Royals first baseman John Mayberry, 6-foot-3 and 220 pounds. Mayberry took the ball, ambled over to the bag to make the third out, but stopped instead of crossing over toward the dugout. The 165-pound Holtzman, running full speed, crashed into Mayberry and went down as if knocked out by Joe Frazier. When Lou Piniella led off the next inning, the still-shaken Holtzman threw the first ball over his head.

Holtzman: “I didn’t know where I was. I was so dizzy and so mad, I thought Piniella was Mayberry, so I threw the ball over his head. When I got back to the dugout, they told me what I’d done.” [Holtzman went on to say that he had hit the back of his head after falling, had bitten his tongue and was still dizzy upon being removed from the game in the sixth inning.]

Piniella is shorter and doesn’t weigh as much as Mayberry, and not only is Piniella white and Mayberry black, but Piniella bats right and Mayberry left.

By the time Mayberry came up again, Holtzman’s head had cleared. He threw a ball over HIS head and then struck him out.