Well George !
It seems when the rules for our matches were written, It seems The STEROID 15 MATCH gives 11 points if you shoot a clean 10, not touching the black. Check rule #6 of the Steroid 15 Matches.
After looking, no extra score is given in the Standing no support Match. A hole in the center of the ten ring, that does not touch any line, is considered a "X" = 10 points. I have posted these rules from Charlotte's post.
I hope this helps,
Bill
Now I know of no NRA Match where extra points are give out, they do have the "X" ring, which is used to break tie scores.