See it was stated in another thread You maths is correct but Its incorrect theory that has no relevance to Xur. Xur picks items randomly There are 2 exotic per item slot for a class there are 3 classes That means 6 items per slot due to this Xur always has a 1/6th chance of picking an exotic He never is affected by previous weeks Saying the % is lower each time is hideously wrong and a bad application of maths. I don't actually believe its a 1/6th as I posted the way i think it most likely organised. However the actual stat is meaningless to the basic function of how an RNG works. It is always 1/6th chance of occurring next week. That is not less probable because of last weak its is EXACTLY 1/6th nothing more nothing less. Under pure random he could do this shit until 2015 xmas. Highly unlikely you might say but its still possible because the equation is always going to be 1/6th or number of outcomes turned into a % or fraction 10 items would be 10% per item 20 items would be 5% per item etc etc