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 - While below 60% Health, you gain an additional 15% Physical Lifesteal for 5 seconds. Can only occur once every 15 seconds.