[TrueSkill] is a skill based probabilistic ranking system developed by Thore Graepel and Tom Minka at Microsoft Research Centre in Cambridge.
scala
val skill1 = Gaussian(4, 81)
val skill2 = Gaussian(41, 25)
val perf1 = Gaussian(skill1, pow(25d / 6, 2))
val perf2 = Gaussian(skill2, pow(25d / 6, 2))
val perfDiff = Gaussian(A = Matrix(1.0, -1), Vector(perf1, perf2), v = 0.0)
val outcomeFactor = Categorical(perfDiff, cdfThreshold = 0, value = 0) //player 1 is a winner
infer(skill1) // Gaussian(27.1744,37.4973)