Bowling is Not Technically a "Sport"

Before you jump down my throat, know that bowling is one of my favorite things to do in my spare time. Many nights have I found myself at the alley with friends knocking pins down and eating chetos. But today I got in a serious argument with a good friend, and it got me thinking. Unlike any other sport that comes to mind (though I'm not denying there could be other "sports" similar to this situation), Bowling is a "sport" of extremely few variables. Which is why I don't believe it should be called a sport. Can anyone think of any other sport with so few uncontrollable variables? This guy I argued with was yelling that the oiling on the floor was a huge variable, and the temperature, and where the machine put the pins down (which I was under the impression is exactly the same on every refresh), but honestly, compared to... say... Water polo, where you've got all these different people who can DIRECTLY effect the other players, you've got water, the elements, the ball, fatigue, the list goes on forever. Basically, Bowling is designed in a way (where nothing really changes between frames) that makes it possible to perfect the game - "beat the game" if you will - because the only real random factor is the one player. So I'd argue that it is possible to, with time and practice, throw perfect strikes every time, game after game. My friend argued that no one's ever done that, but that's besides the point. The point is bowling is the only sport I can think of where that's possible. Comments please.