Lynda Mc Donald writes: Modern Warfare 2 offers its online players the option of picking 3 Perks to use per class in its multiplayer mode. It also allows you to gain the addition of Pro Perks for each Perk. To get a Pro Perk you must complete Perk related challenges while playing online. The majority of the Pro Perk challenges are easy as they require you to just keep using the Perk but some of them can be difficult to achieve.
Picking the right perks to use depends on a few different factors: the weapon you're using, how you play the game and how you intend to play the game. In order to make a good decision on which Perk to use it is best to know the advantages and disadvantages of each as well as what they do.