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 - Each time you Basic Attack an enemy god, gain a stack. When you have 4 stacks, your next Basic Attack damage Slows the enemy god hit by 15% for 2s. Additional Slows applied from this item refresh the duration.