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 reduce your target's Magical Protection by 10% for 3s (max 3 Stacks).
PASSIVE - Basic Attacks and Abilities gain 15% additional Magical Power against targets below 60% Health.