I think I figured it out...not entirely sure though.
For Elite Regular, the minimum speed to qualify is 3.75 YPS for large dogs which I think = 3 YPS for small skilled dogs (who get 25 % more time) so when my small skilled dog ran 4.46 YPS = 95.82 DRI, the same ratio applied to 3 YPS = 64. 45 DRI so in that particular class the minimum DRI to qualify was 64.45.
Does that sound right? It is so cool to be able to see the bigger picture through DRI scores!