On Friday’s broadcast of HBO’s “Real Time,” sportscaster and CNN Contributor Bob Costas stated that boxing federations allowing biological men to compete against biological women “seems crazy.” And noted the oddity of doing so in boxing, a sport with separate weight classes.

Costas began by noting that different sporting federations have different rules.

He then stated, “I understand that, when it comes to Olympic boxing, that federation will allow trans women to compete against biological women — at birth biological women. That seems crazy. And you don’t want to be called — it’s not transphobic to say, let’s inject some common sense here. A lot of this is murky, and we don’t want — we know that some people who use this as an issue actually are hostile toward trans people or people who, after a carefully-considered decision at a certain point in life, decide that they’ll be happier and closer to their true selves. I think any sensitive person is aligned with that. But Sugar Ray Leonard didn’t fight Mike Tyson, they were contemporaries. Sugar Ray was a welterweight, Mike was a heavyweight. If someday, the best player in the WNBA can play in the NBA, everybody would applaud. But if the worst guy at the end of the bench on the worst team in the NBA went to the WNBA and averaged 40 points a game, everybody knows that’s bullshit.”

Costas added that there will have to be codified rules, but he doesn’t know exactly what those should be.

Staff Writer for The Atlantic Caitlin Flanagan then stated that the reason sex divisions in sports exist is due to the differences between sexes, which Costas agreed with.

Follow Ian Hanchett on Twitter @IanHanchett