" I never was very high on any leaderboard, but this doesn't mean I've never been incredibly good at any video game. I was a near-god at Resistance 2 multiplayer. I would, 98% of the time, finish first in every game I played, regardless of type. I came across people who where very high on the board (in the first 30 lets say), and I moped the floored with them. Leaderboards aren't the best way to mesure a person's skills. Sure, it's a neat tool, but often times the people who are at the top are there because they are crazy and play constantly. Still on the subject of Resistance 2, I played this game for several months after its release. The game kept track of how many days, hours and minutes one had played, and I had calculated that, based on the time played by the top dogs on the board, they had to had play the game in average of 10 hours or so per day, and the game was already out for several months. That's crazy. So my point is, often times the top players on a leaderboard are crazy people with no lives. And you should not envy them. "
That's a bit of a different situation, though. With a game that's been out that long that ONLY tracks something that goes up no matter what (meaning, if you had your 4 year old brother hop in the game and not know what's going on but manage to get a kill, that would actually help your total score), then yes, playing time is the dominant factor. However, when you look at the early game, when everyone really has the same chance, you'll see the best players at the top. You have no idea how hard it is to get #1 in a big multiplayer shooter where EVERYONE is trying to play as much as possible. Only the best of the best will accomplish this feat in the early game, and if someone eventually has the dedication to log on 10 hours every single day, then they deserve the tiny bit of reward for an enormous amount of work.
With that said, Black Ops did it much better in terms of FPS leaderboadrs because they ranked it by score per minute instead of total [x]. That way, playing time is no longer a factor (in fact, it can almost be a negative factor) in your rankings. #1's in Black Ops are considerably harder than CoD4/WaW/MW2.