Dunbar came in here as an undrafted rookie, got better every year and therefore got more playing time. When he was ready to start he did start - he started 14 games in 2011. That's exactly what you are hoping for and it's a success story. If you don't want to give Vitt any credit for that then you are free to do so but Dunbar's career clearly shows that young players did get better under Vitt.