Help with Doom Leaderboards

I bought this game with my 400 MS points and i love Doom. I always have. Even when i was a baby. But idk. I played online a few times on Deathmatch but i never finished a game. I dont know if there is a time limit or a kill limit so i just quit when i got bored. And when i go to the leaderboards and it says im not ranked on the leaderboards. Why is this? Is is because i never finished a game?