Just watched Path to the Draft on NFL Network and Charley Casserly presented an interesting study he's been doing over the last ten years. Basically he looks at the percentages, per round, to get a starter after 4 years.
1st. 75%
2nd. 50%
3rd. 30%
4th. 25%
5th. 25%
6th. 9%
7th. 9%
What sticks out for me:
There is a big drop off from the first to the second.
There is not much difference between the third, fourth and fifth.