Does he like me or is he just playing head games?

[Angel C]

I'm in high school, I'm in 10th grade and the guy I like (Mike) is in 11th grade. There's this guy in my lunch. Well actually 4. And one of them looks at my friend and another (Mike) usually looks at me. Mike is a really cute guy. I added him as a friend on facebook and he accepted my friend request. He has like 600 friends on there and I only have about 200. So he's kinda popular at our school. He plays baseball, the pitcher. And in lunch he looks at me a lot (REALLY A LOT). Sometimes he faces me and sometimes he doesn't. When he does, I catch him staring at me, he always looks me in the eye, sometimes he'll keep the eye contact and other times he'll look away as soon as I see him looking at me (and vice versa with me). Then, when he doesn't face me, he'll turn his head around and look at me sometimes, but he looks at me more when he faces me. Then my friend said that one day he was behind me and he was "checking me out" while I was on the lunch line and he happened to be alone that day and not with his friends. But then he acts weird and some days he'll look at me a lot and then other days he won't. And the other day, I was playing tennis in gym and I didn't have a partner, so I was playing on my own team, so one of Mike's close friends (who had his own partner and was already playing tennis) came up to me and said "can I be your partner?" and I said "sure, then his friends he was playing with said "WTF are you doing?" and he's like "she needed a partner", so his friends didn't understand why he did that, and neither did I. Also, when I see him in the hallway sometimes me and him make brief eye contact and then other times he won't give me the time of day. I find that when he's by himself, he seems a little nicer towards me. But also, what I don't understand is the fact that he isn't really shy. The guy that looks at my friends is very shy, but he obviously isn't. I look at his profile on facebook since we're friends on there and girls write on his page all the time and he'll usually respond to them (but they're also popular girls too). But I never really see him talking to girls in school, only like once or twice I did. But I don't understand why he can't talk to me. Why? If he's not "shy"...I don't understand. And also, why does he act like a jerk to me sometimes, like lately he hasn't been paying any attention to me. But then he'll do that for a few days and then he'll completely change and just keep staring at me. I'm a shy girl so I don't think I'd have the guts to talk to him first. But what do you think is the problem here? Like, does he like me? Is he just playing head games with me? Does he not notice me and I sound crazy right now? I really don't understand why he acts the way he does....but I'm too shy to just go up to him. *Sorry this is so long, I just want the best possible answers so at least I can have an idea w/out actually asking him.*