I just listened to a radio interview of Reggie Jackson who threw the ceremonial first pitch today at Yankee Stadium.
During the interview, Reggie admitted that he was this close to not re-signing with the Yankees after they won the 1981 World Series. Had they lost that World Series to the Dodgers, he definitely would have left. Instead, he signed a new contract to continue wearing the pinstripes for another three years and became the highest paid baseball player at the time.
Of course, the Yankees repeated as World champs in 1982 and 1983. In 1984, the Yankees fell to third place and George Steinbrenner fired manager Yogi Berra and re-hired Billy Martin. Reggie had enough and signed a two year deal with the Kansas City Royals. They won their only World Series title in 1985. By 1986, Reggie struggled at the plate while being the full time DH. He played his last season in 1987 with the A's.
Had Reggie chose to leave New York in 1981, would the Yankees still have won those titles in 1982-1983 or if he had signed with the Angels (where he would certainly have ended up), would he have led them to the World Series?