I dont know if this has been done before, but I have just computed some pobability charts. Might come in handy for a GM.
1st: Probablity to reach or exceed a certain treshold y
2nd: Probability to win or dra with x dice in an opposed test versus y dice
3rd: Probability to win in an opposed test versus y dice
find it here: http://www.serbitar.de/stuff/probabilities.pdf
All possiblities from 1-12 dice.