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 - Physical Critical Strikes bonus damage taken is decreased by 40%.
PASSIVE - Your Critical Hits provide you with 10% Physical Penetration for 4s.
AURA - Enemies within 55 units have their Attack Speed reduced by 25%.