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 Critical Hits provide you with 10% Physical Penetration for 4s.
PASSIVE - Critical Strike bonus damage dealt is increased by 25%.
PASSIVE - Your first ability cast gains 20% Physical Penetration. This can only occur once every 5 seconds.