Additionally, is is a little information for Leyline of the Void if you are determined beyond all reason to open the game with one against Flash.

Probability you get one in opening 7:  33.63%
Probability if you mulligan to 6:           53.89%
Probability if you mulligan to 5:           66.29%
Probability if you mulligan to 4:           73.96%
Probability if you mulligan to 3:           81.25%
Probability if you mulligan to 2:           83.62%
Probability if you mulligan to 1:           84.71%


This statistics doesn't seem really logic, you have more chances to draw a leylline mulligan into 1 card? wtf? this can't be real.