You can read about how Call of Duty: Black Ops II changes multiplayer class-selection with the introduction of a pick-10 system. It’s all explained right here. Or you can just stare at this board game prototype of the system from the creators of the game.
https://kotaku.com/black-ops-ii-multiplayer-blowout-scorestreaks-replace-5934476
The only thing that would make this better is if this board game was the only way to pick your Call of Duty class and all of the load-out items were actually Skylanders-like statues that had to wirelessly communicate with the board. Right? Right??