It's 10 because that's the way numbers on a standard dartboard are arranged, starting from the top and moving clockwise. It seems like WolfBlitz knew this, but for some reason didn't want to admit he knows what a dartboard is, or something. There's no real mathematical logic behind why it is arranged this certain way, which is why it doesn't make much sense that he is absolutely sure it's 10 because it "fits" (since it doesn't).
But by splitting up the numbers randomly, between high and low, it makes it more challenging. If they were just in numerical order, you'd aim for the area 15-20 and guarantee a decent score as long as you hit in that range. Someone just picked a randomized assortment of the 20 numbers and everyone else went along with it.
WolfBlitz2
I know your pin number!
it is ****
for security reasons some numbers a hidden
flashman16
you made another funny!
so here's a joke...
whats black and white and red all over?
(i'll let you make a guess!)