Odds of matching from a pool of 21

[Frank]

I did mention this in one of the challenge contest threads, but I'll repeat it here for reference :-

I the Pick 21 challenge I have an extra scoring system (under test, just for fun) that allocates 21 points for a hit in the leftmost position, 20 points for a hit in second position , etc... down to........ 1 point for a hit in the 21st position, but nothing for a bonus ball outside the first 7 positions. The maximum score available is 126 for match 7 in the first 7 places.



In this example the positional score is 13+12+11+10+3 = 47.