Rare would be less than 5%.The % of Cal freshman returning who have a chance to be drafted, that return is pretty low. That qualifies are rare to me.
I can count T.Jones, Poythress, WCS, PJ
Good players who had a chance to be drafted, but probably wouldn't have been include: Lamb, Andrew, Aaron, WCS after FR year, Miller, Lee (I remember him going onto draft boards after those 2 good tourny games), Hagans, Oscar.
Those are not "Rare" numbers. "Low" and "Rare" are very different words.