On February 20 the Web site Baseball Prospectus scooped the dailies by reporting that Cubs starting pitcher Mark Prior was having shoulder trouble. Cubs GM Jim Hendry and manager Dusty Baker initially denied the report. “You can’t believe a report unless it comes from us,” Baker told the media the day after the story appeared. “If it doesn’t come from us, it doesn’t count.”

So on March 15, when the Cubs announced Prior was indeed having shoulder troubles (he remained on the DL at press time), Christina Kahrl could have gloated a little. She’s the managing editor of Baseball Prospectus, which she founded with four other stats-obsessed writers in 1995, and tens of thousands of readers knew they were right. But Kahrl was more philosophical about the Prior event. “We’re not looking for scoops,” she says. “It’s more of a think-tank business model, where we want to talk about what’s going on and why.”

Mark Prior was Baseball Prospectus’s biggest story of the past year. The second biggest was Kahrl herself. When she was living in Chicago, where she helped assemble the Baseball Prospectus staff, she was Christopher Kahrl. She moved to the D.C. area in 2000 to work for a sports-book publisher, and the following year she decided to change genders. Currently a preoperative transsexual, she’s been living as a woman since 2003. She first went public about her sex change in August, when she used her new byline on a piece about the Oakland Raiders in Salon.

That didn’t go unnoticed among the stats geeks who pay close attention to Baseball Prospectus’s hard-core numbers juggling. Bulletin boards and blogs picked up the news, but Kahrl, 38, would just as soon play down its importance. “It is interesting, but it isn’t important,” she says. “Readers are still reading the same content. I’m still writing the same content. I’m sure there’s people who say, ‘Well, you don’t see that every day,’ and you don’t. But we live in a different world than the way things were 50 years ago.”

Kahrl informed many of her colleagues of her decision via e-mail in 2003. “No one expected this kind of revelation,” says Rany Jazayerli, a Naperville-based senior writer. “After I got the e-mail, the first thing I did was call her. It was not my position to agree or disagree with what she did. The best thing I can do as a colleague is to understand what she was going through. The only concern we as a group had was, ‘How is this going to affect us in baseball?’ Baseball is a fairly insular sport and we were becoming well-known in the industry. What would people think when word got out?”

Nate Silver, who works out of Lincoln Park as Baseball Prospectus’s executive vice president, had similar concerns. “I’m a liberal guy, but at first you question your own tolerance,” he says. “There’s a bit of a shock the first time you see a picture or read about it, but once you’re down talking baseball and working with someone every day, you don’t think about it. Once in a while I slip in ‘Chris’ instead of ‘Christina,’ but apart from that it has been surprising to see how tolerant people have become.”

“This is the one thing I needed to iron out,” Kahrl says. She notes that her family was just as supportive as her colleagues. “If any family was going to be open-minded, it was probably going to be mine,” she says. “My brothers have been great and so have my parents. My grandmother’s line was, ‘Well, you’re the first one in my family I know about–and I love you just the same.'”

In the early 90s Kahrl, who grew up near Sacramento, California, was working at the Oriental Institute Publications Office on the University of Chicago campus (she has a BA in history from the U. of C. and a master’s in public history from Loyola). She posted regularly to the rec.sport.baseball Usenet group. Impressed by their baseball knowledge and writing talent, baseball consultant Gary Huckabay assembled Karhl, Jazayerli, and three other regular posters in 1995 to create a baseball annual designed to replace Bill James’s Baseball Abstract, the pioneering stats compendium that stopped publishing in 1988. “We had all been without the Abstract,” Kahrl says. “We’re all on the same page when it comes to using objective knowledge to come to concrete conclusions.”

The Baseball Prospectus site and the first edition of the book both appeared in 1996. This year’s book contains analysis of 1,600 players, including minor-leaguers, draft choices, and in-depth chapters on every major league team. Baseball Prospectus annually ranks as one of the best-selling books during spring training, and the site gets about 27,000 unique visitors a day throughout the season. Still, it’s not for everyone–along with articles and essays is an alphabet soup of stats and acronyms, the best known of which is arguably PECOTA (Player Empirical Comparison and Optimization Test Algorithm), a statistical system that projects a player’s performance using a database of players going back to World War II. According to Silver, 28 of the 30 major league teams subscribe to the Web site; in her foreword to the latest edition of the book, Kahrl sends shout-outs to the GMs of the Seattle Mariners, Toronto Blue Jays, and the Cubs.

Kahrl is an Oakland A’s fan, but in Chicago she attended between 20 and 30 games at Comiskey Park and a half dozen more at Wrigley Field, each season. She still takes in Sox games when she visits; last July she and Silver took part in a U. of C. alumni trip to Sox Park, where they spoke on Baseball Prospectus’s performance analysis method. “We broiled in the sun watching [Jose] Contreras perform an homage to Steve Trachsel in terms of taking his time between pitches,” she says.

Kahrl and her cohorts strike a similar tone in their pieces for Baseball Prospectus, including her weekly column, “Transaction Report.” Regarding Red Sox pitcher David Wells’s recent move to the DL, Kahrl wrote: “I wouldn’t get too worked up over Jumbo’s latest breakdown. The man’s going to be 43 in another month, he’s never going to be light on his feet.”

“If you don’t do that, it would be like reading a fantasy baseball magazine or a corn futures report,” she says. “That’s one reason I don’t like fantasy baseball. I understand we’re talking to a predominantly fantasy market, but I’m interested in what the players are really worth to their teams. I don’t care if he will help you win a category. I guess I’m just more interested in real life.”

Baseball Prospectus has a staff of 30, including three interns; only two were women before Kahrl switched genders. She’s thought some about her new status as a minority member of the sports media. “In some sense I am the singular member of the team,” she says. “I would like to see more. As a kid I remember Gayle Gardner [ESPN’s first female on-air staffer] and how cool she was.” Silver adds that Kahrl’s gender might influence the next generation of sportswriters. “Baseball is still something of an old boys network in the media and the industry itself,” he says. “But when some old beat writer retires, you might have a 25-year-old take over who has read our stuff or other things. They will come in with more of an open mind.”

Art accompanying story in printed newspaper (not available in this archive): photo/Charles Steck.