What reasons do you like this guy? Do you know yourself? Do you know anything about him past what he looks like or have you ever chatted and gotten along? Are you even friends at all past mere teacher and student acquaintanceship? And what kind of something do you want? Have you thought about it? A quick one night stand or a long lasting romantic relationship?
I don't know, to me, I feel you need to stop pining and wanting the attention/validation from people you obviously do not click with.
I doubt too this is even a competition to anyone other than you, in your own mind. First off, answer the first question seriously as to why, then ask yourself if you've even made any notion of it to him or anyone else, past just what rushes through your mind.
You can't be in any competition if you don't even play. Also, real life romance doesn't work the same way as bad television where the nice girls goes up against the popular ***** and then everyone knows it, etc.
You say he's flirted with them, which right off the bat is highly inappropriate for any professor to do in a school setting, let alone ever being with one of his students; college or not, so what exactly does this flirting actually entail?
When I was younger, I thought 'flirting' meant just two people getting along and having a nice chat, or is it outright serious flirtation, with a bit of grabbing, obvious interest, etc.
I've been where you were when I was younger and frantic, so somehow I think it's the former that you're mistaking simple pleasant conversation of chemistry between them as romantic flirting. Correct me if I'm wrong.
And if I am, that is some serious misconduct on the behalf of a professor, which is a huge red flag. That is not a guy who's into romance, to me.
Anyway, simply vilifying others or scapegoating them doesn't help your situation. Either start talking to him, gauging how well you get along, which is the best way you can hope to actually form a connection that can lead into more with him. If you don't click naturally, and he likes those other types of girls, sorry, it won't work with him.
You should start trying to find more people who are of similar mind and interest to you; they're the ones you can really be friends with that can lead to something more that IS genuine.