When Sammy Sosa was recently caught using a corked bat in a game, there were some players who felt that he was using it intentionally and expressed sadness that he was caught, not that he was cheating.  When Jose Canseco and Ken Caminiti came out with testimonials about the widespread use of performance enhancing substances in major league baseball, the public was shocked that so many baseball players would break the rules.  The players, though, were more outraged that Canseco and Caminiti had revealed something that should have stayed in the clubhouse.  Whether it's the long season, the slow pace, or the fact that baseball has been around for so long, major league players tend to be especially sensitive to the way things look, which fuels an “honor code” that may appear confusing to outsiders. 

A few decades ago, if a player hit a home run, the pitcher would occasionally bean him the next time he came to the plate.  Sometimes he would even plunk the very next batter.  Hitting a home run, you see, makes the pitcher look bad, and anyone who makes the pitcher look bad deserves a fastball in the ribs.  We've gotten away from that particular practice in recent years, but anyone who watches baseball knows that there can be severe penalties for showing someone up or running up the score.  Often, the only action that is smiled upon in baseball is violent retaliation on the part of the violated. 

Ownership of the inside part of the plate is the most common battleground on which feelings often get hurt.  Participants in any sport feel justifiably angry when they are being targeted by another team, but baseball's batsmen have extended the “zone of distress” from being hit intentionally to pitching inside.  As batters (often emboldened by body armor) have moved closer to the plate, the pitchers perceived motives have changed.  Now, the pitcher who is trying to hit his spots inside is seen as trying to make the batter uncomfortable, and the pitcher who had been pitching close to make the batter uncomfortable is seen as trying to hurt the batter.  Consequently, the opposing pitcher retaliates by hitting one of the other team's players, then that player charges the mound, and we have a bench-clearing brawl.  Though the brawl is the most flagrant part of the whole episode, players usually look upon it as doing their job once one of their guys has been made to look bad. 

Though the batter is most often dishonored, the pitcher has several different ways to get his feelings hurt.  Imagine a player who can get offended when he can't get anyone out (he's behind in the game) and he can't put the ball over the plate (there's a 3-0 count) and someone actually finds one of his pitches acceptable enough to swing at. 

And then there's Curt Schilling, whose perfect game attempt in 2001 was ended in the eighth inning by a bunt hit from Ben Davis.  Schilling's teammates and manager were furious that the pitcher was “shown up” in such an obvious way and that the player who broke up his perfect game didn't earn it.  Davis, along with virtually every sportswriter and fan, wondered how his bringing the tying run to the plate in a game that would have given his team the division lead was showing up the pitcher. 

Pitchers no longer hit people for hitting home runs, but they do get upset if a player hits a home run and fails to round the bases quickly.  A player who stands to watch his ball leave the park is accused of “admiring his shot” which is, of course, a form of showing up the pitcher.  A batter who runs the bases slowly or celebrates on the way around the bases is also considered to be taunting the pitcher.  The most famous example of this may be the Giants’ Jeffrey Leonard, who slowly trotted the bases with one flap down (one arm was limp at his side) during the 1987 playoffs, before and after being plunked by Cardinals pitcher Bob Forsch. 

Baseball is of course a team game, and damage to how the team looks can fuel the most bitter confrontations.  While home run hitters draw the ire of pitchers, base stealers can set off the entire team.  If there is one unwritten rule that almost everyone agrees upon, it is, “Thou shalt not steal bases when leading by a lot (“a lot” is usually defined as more than the value of a grand slam) late in the game.”  Rickey Henderson did this against the Brewers in the seventh inning of a 12-5 game, and the Brewers' manager threatened him with a “drilling.”

Strangely enough, the Cardinals and the Giants, the same two teams that would clash over unwritten rules in the playoffs, had a famous and telling bout over stolen bases in the 1987 regular season.  Whitey Herzog loved to live by the stolen base, and he had his Cards stealing bases in the fifth inning with a 10-3 lead.  Roger Craig, whose Giants were cut more from the three-run homer mold, was furious, and he expressed his anger that his team was being shown up.  Amid the bench-clearing brawl, Herzog responded that his team would stop doing what it did (trying to steal bases) if Craig would stop his team from doing what it did (trying to hit home runs).  The Cardinals won the game 10-8, and they retired the final out with the tying run on base. 

Even umpires have their own unwritten rules about when they are being shown up.  For most umps, the general rule is that a player should not draw attention to an umpire during a game, which most often means arguing balls and strikes with the home plate umpire.  And umpires don't fight or complain; they punish.  Umpires have been known to change the strike zone for pitchers who have embarrassed them and to make bad calls to retaliate for a player's dissatisfaction with a particular call. 

Virtue and vice are often viewed as absolute terms, but in baseball they are relative and somewhat inside.  To us, vice is about the propensity to do real harm, but in baseball it is more about perceptions and situations.  Baseball's vices are an example of what can happen when you mix tradition and egos in front of thousands of people 162 times a year. And though it may seem silly to you and me, baseball players guard these unwritten rules as if they are preserving the game itself.