*sigh*
As I said, pig ignorance.
Chromosomes are neither as simplistic, nor as straightforward as you have made it out. What did you do, make a Punnett Square of XY and XX, and then assume you've got it all figured out? Oh, of course, make a Punnett Square! XX and XY, no others need apply! Genetics can be figured out with a square I can show a 12 year old! Damn fools spending thousands of dollars getting degrees in this stuff, what a bunch of stoned wankers.
Too bad genetics doesn't quite work that way. Y genes are not necessary to be male. All you have to have is one X gene. XO is... drumroll... Female. One X chromsome. XXY? XYY? XXYY?
Oh, wait, this is the very tip of the iceburg. I'm sure you can use your incredible ignorance to assign a gender to all of those.
But how about XX/XY? Mosaics. Yes, genetics is not even as straightforward as you having a single set of genes. Mosaics occur in early development, and result in an individual with both XX and XY parts of the body.
Oh, I'm sorry, they're XY. They're male. I remember. I mean nevermind the fact that the individual is a woman who can have kids. She has an XY right arm. Sure, there's no glands in the right arm. Sure, it basically has absolutely no influence on the woman whatsoever. But, XY! She's definitely got XY genes. Male.
It gets even more complicated then this. I haven't even SAID the word Chimera yet (I just did. It makes life more complex. Lets leave it be, because you're ignorant enough already, that'll just get you confused).
The International Olympic Committee convened a group of biologists and scientists to discuss this. They reached the conclusion that there is no standard or sets of standards that define a gender.
But I know! You're smarter than all those scientists, have more expertise in biology, and more knowledge! That's why you know the earth was created 6,000 years... err... you can define gender!
Pig ignorance. It's not a virtue.
Wow! Just wow! Thank you for that.
Of course there is a standard test to define a gender. XY is male, XX is female. The rest is neither. For the purposes of competition, they have to be "assigned" as being either male or female by the competent authority based on individual tests. Which is exactly what's happening with Semenya. Scientists are doing those tests.