Facts about FPSs

3 Step guide to FPSs
There are 3 basic steps to becoming good at a first person shooter:
1) Basic FPS skills
This means learning the basic movements of the keyboard, WSAD keys, mouse, aiming, reflexes, "R" for reload, bunny hopping, strafing, etc. These skills usually apply to most FPS shooters and therefore are universal.
2) Specific Game Skills
In Counter-Strike, you aim for the head. In AA, you aim for the torso. Each game has different gameplay properties, so it's basically impossible to be good at AA and CS at the same time unless you have some kind of "double" mind that can switch games. So, you have to learn what works, what doesn't, and anything else specific to that game.
3) Specific Map Skills (strategies)
Every map is different. You need to know where the battle lines are drawn, where the strategic points are, how to flank, and the best camping spots. Even the most skilled player can get killed by an unskilled player because the skilled player doesn't know where to go or what to do on that map. "Skills" may save you in the beginning, but learning the map will make you 5x better on that map.
In Counter-Strike, map strategies have existed for years. Everything is basically common knowledge.

Skill vs. Tactics
To be good at CS you have to have about 80% skill, 20% tactics. Running and gunning and learning how to headshot will save you in many situations. Without those skills, you'll die no matter how smart your strategy is.
In America's Army, you need about 60% skill, 40% tactics. This means that the player with the smarter head, and the better maneuvers can kill the whole opposing team by himself. This can be true in CS, but the element of surprise is much greater in AA.
In america's army, it is MUCH harder to tell where you're getting shot from, and you can take on 5 guys at once. But in CS, you always know where you're getting shot from, and it is much harder to take on multiple enemies. Thus, America's Army is an easier game to go solo in.

Maybe more later...