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 - Basic Attacks and Abilities gain 15% additional Magical Power against targets below 60% Health.
PASSIVE - You gain additional Magical Power and Lifesteal scaled from missing Health. This caps at 70 power and 10% Lifesteal at 40% Health.
PASSIVE - Your Basic Attacks reduce your target's Magical Protection by 10% for 3s (max 3 Stacks).