The pinstriped teammate treaty between Kevin Youkilis, the Yankees’ new third baseman and former Red Sox star, and Joba Chamberlain, once suspended for firing two fastballs over Youkilis’s head, evolved from a kindergarten spat compared with what went on between Carl Furillo and his longtime tormentor, the New York Giants right-hander Sal Maglie, before they suddenly became teammates on the Brooklyn Dodgers in 1956.

In the first part of the 1950s, the Dodgers and the Giants won six consecutive National League pennants between them — the Dodgers four and the Giants two. They were raging rivals who, to be polite, didn’t like each other, and they demonstrated that dislike in 22 regular-season games every year.

“Except for an occasional hello to Gil Hodges, when we’d walk past the Dodgers going to and from our clubhouses under the stands at Ebbets Field, I never spoke to any of them,” Bobby Thomson, whose home run won the 1951 pennant for the Giants, once said. “We just didn’t like each other.”

Of all the Dodgers, Furillo, in particular, didn’t like the Giants. He didn’t like Leo Durocher, their manager. He didn’t like Maglie, the Giants ace known as Sal the Barber for how his pitches shaved opposing batters’ chins.