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.
Increase your maximum Health by 120.
Increase your Movement Speed by 10% for 4s after getting a Killing Blow or Elimination.
Increase your maximum Ammo by 2.
Decrease the time between bursts of Dead Ringer's inhand fire by 16%.
Increase the duration of Dead Ringer's reveal on destruction by 2s.