This is what I call useful groundbreaking research:
Around the world, at all ages, boys throw better — a lot better — than girls. Studies of overhand ball throwing across different cultures have found that pre-pubescent girls throw 51 to 69 percent of the distance that boys do, at 51 to 78 percent of the velocity. As they get older, the differences increase; one U.S. study found that girls age 14 to 18 threw only 39 percent as far as boys (an average of about 75 feet vs. about 192 feet).
So "You throw like a girl" might be sexist on the one hand and homophobic on the other, but that doesn't mean it's not a valid criticism.