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 - When critically striking an enemy, gain a stack of 5 Physical Power, max 3 stacks, for 5s.
PASSIVE - Your first ability cast gains 20% Physical Penetration. This can only occur once every 5 seconds.