In Call of Duty 4: Modern Warfare, each player is given 3 perks. Perks are added bonuses to give each player their own unique abilities. Here is a list of recommended perks for call of duty 4.
Assault:
- Perk 1: Special/Fragmentation Grenades (x3)
- Perk 2: Juggernaut
- Perk 3: Martyrdom
You will have either 3 Frags or Special Grenades. Juggernaut will give you some extra health. This is very useful if you are using the Assault class. Martyrdom drops a live grenade upon your death. This is especially useful if you are in a map like Shipment.
Tactic/Light Assault:
- Perk 1: Special/Fragmentation Grenades (x3)
- Perk 2: Double Tap
- Perk 3: Extreme Conditioning
This class has weapons that have good mobility. Double Tap is very useful in this class. It increases the rate of fire, allowing you to kill close enemies very quickly. Extreme Conditioning will help you sprint for longest distances, to help to get out of those tight spots.
Sub Machine:
- Perk 1: RPG (x2)
- Perk 2: Sleight of Hand
- Perk 3: Deep Penetration
RPG's are good to have, especially if the opposing team calls in a Chopper. It will help bring it down faster. Sleight of Hand makes you reload drastically faster. Since Sub Machine guns take forever to reload, this is a vital skill. Deep Penetration increases the velocity of your bullet. With the strong Sub Machine gun and Deep Penetration, you will easily kill anybody behind thin walls.
Sniper:
- Perk 1: Claymores (x2)
- Perk 2: UAV Jammer
- Perk 3: Iron Lung
Claymores are vital if you are a sniper. Snipers usually camp in an area for a while. Planting claymores around you will help kill enemies that get too close. Since your position is revealed after every shot you take, UAV Jammer is important to have. You don't have to worry about giving away your position after every shot. Iron Lung helps you hold your breath longer, so you you'll make a better shot.
Shot Gun:
- Perk 1: Special/Fragmentation Grenades (x3)
- Perk 2: UAV Jammer
- Perk 3: Martyrdom
Well the perks above are pretty much explained already.
If you get a 3 kill streak in one life, you are rewarded UAV radar for 30 seconds. This reveals the location of your enemies (that is if they don't have UAV jammer). Even if you die before you get to use your radar, you can still activate it during your next life. This is the same for Airstrikes and Choppers. You are rewarded with an Airstrike if you get a 5 kill streak in one life. An Airstrike can only be done over a certain area, so it's best that you wait for somebody to activate UAV radar before you use it, so you know where to attack. A 7 kill streak will reward you with a Chopper. The Chopper will stay in the air for a good amount of time, unless your foe's shoot it down. If your Airstrikes or Chopper kills any players, you are rewarded the points for those kills.