This is our proprietary skill rating calculation. This has nothing to do with official game ranking or MMR.
The purpose is to show player skill levels relative to other players, not estimate MMR.
PASSIVE - Your Basic Attacks benefit from an additional 20% Physical Penetration.
PASSIVE - Critical Strike bonus damage dealt is increased by 25%.
PASSIVE - Protects you from a single hard Crowd Control effect once every 70 seconds. When this occurs, you gain 1s of Crowd Control immunity.