1.0. Don’t embarrass yourself, your teammates or your opponent.
1.1. Never show up an umpire on balls and strikes.
1.2. Never steal a base when leading by a bunch of runs. Rickey Henderson was the all-time offender, once taking second base with the Brewers’ defense playing back and his team leading 12-5 in the seventh inning. “There are certain things you don’t do,” Milwaukee manager Davey Lopes said. “You don’t stop competing; what you stop doing is manufacturing runs.”
1.3. Never show up an opposing pitcher after hitting a home run off him. This is includes such no-nos as Ruben Sierra’s funky-chicken dance step and Jeffrey Leonard’s one flap down. Taking a long time to get around the bases is considered taboo. Scott Rolen of the Cardinals is one who does it the right way — drop the bat and run around the bases.
1.4. Always run onto the field in support of your teammates or players after a fight breaks out. Indians manager Charlie Manuel once was suspended for two games for running onto the field from the clubhouse.Manuel had been ejected from the game but said he could not in good conscience stay in the clubhouse while his players were throwing haymakers.
1.45. Don’t fraternize with opposing players.
1.45. (a) Players who don’t run onto the field in support, or who fraternize with opposing players, shall be fined by a kangaroo court.
1.45. (b) Kangaroo courts shall exist in every major league clubhouse and operate by their own set of unwritten rules. See Jay Buhner, Mariners, 1988-2001.
2.0. Play the game the right way.
2.1. Never lay down a bunt to break up a no-hitter. Ben Davis, then with the Padres, did this against Curt Schilling, then with the Diamondbacks, in the eighth inning of a 2001 game. The single brought the tying run to the plate, but Davis was heavily criticized — even his manhood was called into question. “Ben Davis is young and has a lot to learn,” Arizona manager Bob Brenly said. “That was just uncalled for.”
2.2. When breaking up a double play, always go in with a clean slide. Rangers catcher Pudge Rodriguez went out of his way to take out Cleveland shortstop Omar Vizquel in 1994; Vizquel suffered torn knee ligaments, spent seven weeks on the DL, and the Indians were fighting mad.
2.3. Always throw a fastball on a 3-0 count.
2.35. Never swing at a 3-0 pitch when your team has a comfortable lead.Vladimir Guerrero swung at a 3-0 offering in a 2001 game against the Mets with his team leading 10-0, and pitcher Turk Wendell promptly drilled him.
2.4. Never put the tying or go-ahead run on first base.
2.45. Unless you are playing the Giants and Barry Bonds represents the tying or go-ahead run.
2.5. Never make the first or third out of an inning at third base.
2.6 Always run out ground balls, even routine ones. Hustle in, hustle out. This rule does not apply to all; Ken Griffey Jr., for example, never read the unwritten rules during his stay with the Mariners.
2.7. Never interrupt a pitcher’s focus by talking to him before a start.
2.75. Applicable to broadcasters and players alike, never mention “no-hitter” when a pitcher has one working.
2.8. Never steal another team’s signs — or at least never get caught doing so. It is particularly taboo for the batter to peek at the catcher’s signs from the batter’s box. Stealing signs from second base is considered gamesmanship but still requires retribution.
2.9. Pitchers must work inside to keep opposing batters honest but must never throw at a batter’s head.
2.95. Pitchers must retaliate for egregious acts committed by opposing pitchers.