While experts polled by the New York Times’ Alan Schwarz pour cold water on suggestions ballplayers who suddenly improve should be tested more often for use of illegal PED’s, Styles writer Mireya Navarro tackles the thorny matter of Andy Pettitte and Roger Clemens’ current relationship. “Friendship hasn™t been this fraught since the days of Linda Tripp and Monica Lewinsky” writes Navarro. Sorry, I don’t get the analogy.

To many psychologists and sociologists who study male relationships, this rift is an oft-told tale. In less-rarefied worlds ” the office, college, a poker group ” these experts say, men face similar choices: When do you rat out a pal? When do you stop a friend from harming someone? When do you take one for your buddy?

œThese are moments when there™s a clash between two conflicting values connected to masculinity, said Michael S. Kimmel, a sociologist at State University of New York at Stony Brook and author of œThe Gendered Society. œNo. 1, you always do the right thing. And the second is, you never betray your friends.

œWhen a Serpico comes along, he said of Frank Serpico, the cop who blew the whistle on corruption in the New York City police department in the 1970s, œhe™s both a hero and a villain.

Scholars who study gender differences say that when deciding how far loyalty should go, men make calculations on a case-by-case basis rather than on any gender-specific prescription. Are jobs and livelihoods on the line, as in the insider-trading scandals in which co-workers testified against one another? Is the friendship more valuable than personal fulfillment, as in the case of a man who pursues his friend™s wife?

For athletes, the calculus is complicated by an unspoken code. Teams need to be cohesive to work together, sports sociologists noted. It is what has kept teammates, both male and female, they said, from speaking out publicly ” not just about illegal or unethical acts like steroid use but private matters like the sexual orientation of a teammate or an affair between a teammate and a coach.

œThere™s a tendency to protect a teammate or the organization, even at the expense of higher moral principles, said Faye L. Wachs, a professor at California State Polytechnic University, Pomona who specializes in sports sociology.

Jim Bouton, a pitcher and the author of the 1970 baseball memoir, œBall Four, said men become œlike family and you stick up for each other.

When his book exposed amphetamine use, heavy drinking and fighting among players, Mr. Bouton was labeled a Benedict Arnold by the baseball establishment, some ex-teammates and the press, but he never considered his book an act of betrayal.

œThere are things I didn™t put in the book because I thought they™d violate the players™ confidences too much, said Mr. Bouton, explaining that his goal had been to share what it was like to be a ballplayer, which he was with the Yankees and the Seattle Pilots. He described the experience as mostly œfun.

Mr. Bouton said he doubted that Mr. Pettitte would go out of his way to hurt his friend. But if he has information and he is at risk of perjury, Mr. Bouton predicted, œhe™s not going to jail for Roger Clemens.