That's really interesting. I wonder if those percentages will increase as baseball becomes more analytically minded and need/ plan for more fungible arms as relief (and often starter) depth.
Randomly choosing three drafts shows how important (and interesting) the draft can be. The 2013 Reds' draft had 12 guys make the majors-- that would seem like a lot. But a couple of them did it with other teams. Of the 10 left, only three have bWAR over 1.0. The 2005 draft had eight earn at least a cup of coffee at the MLB level, five of which earning over 1.0 bWAR. The 1999 draft had six players make it overall. (Did anyone know the Reds actually drafted Rich Hill? I did not.) Only two of them earned a career bWAR over 1.0.