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 - You gain 15% of your maximum Health and Mana over the next 3 seconds when you get a kill or assist against an enemy god or Objective.
PASSIVE - While below 60% Health, you gain an additional 15% Physical Lifesteal for 5 seconds. Can only occur once every 15 seconds.