...You can essentially think of it as flipping a coin (50% of the time you get 18 and 50% of the time you get 19)...
I am quite sure 18 and 19yo players are
not evenly distributed in the draft. It is more like a
2:1 ratio in favor of 19 year-olds. This is pretty easy to check actually.
17/48 18 year-old players seems normal.
BBB: 2 (S37 S38); Top tier: 7 (S35 S36 S37 S38 S39 S41 S63); Cup: 9 (S25 S35 S36 S37 S38 S39 S40 S41 S61)