9f12c) Change 1/2 for multi BLD to DNF.

Resolves issue #105.

wca-regulations-2013.md

@@ -219,7 +219,7 @@ Note: Because Article and Regulation numbers are not reassigned when Regulations
     - 9f12) For "Best of X" rounds, rankings are assessed based on the best result per competitor. The following are used to compare results:
         - 9f12a) For timed results, "better" is defined as the shorter time.
         - 9f12b) For Fewest Moves Solving, "better" is defined as the shorter solution length.
-        - 9f12c) For Multiple Blindfolded Solving, rankings are assessed based on number of puzzles solved minus the number of puzzles not solved, where a greater difference is better. If the difference is less than 0, the attempt is considered unsolved (DNF). If competitors achieve the same result, rankings are assessed based on total time, where the shorter recorded time is better. If competitors achieve the same result and the same time, rankings are assessed based on the number of puzzles the competitors failed to solve, where fewer unsolved puzzles is better.
+        - 9f12c) For Multiple Blindfolded Solving, rankings are assessed based on number of puzzles solved minus the number of puzzles not solved, where a greater difference is better. If the difference is less than 0, or if only 1 puzzle is solved, the attempt is considered unsolved (DNF). If competitors achieve the same result, rankings are assessed based on total time, where the shorter recorded time is better. If competitors achieve the same result and the same time, rankings are assessed based on the number of puzzles the competitors failed to solve, where fewer unsolved puzzles is better.
     - 9f13) For "Mean of 3" and "Average of 5" rounds, rankings are assessed based on the ordering of the averages/means of the competitors, where "better" is the shorter recorded time.
     - 9f14) For "Mean of 3" and "Average of 5" rounds, if two or more competitors achieve identical average/mean results, rankings are assessed based on the best attempt per competitor, where "better" is defined as the shorter time.
     - 9f15) Competitors who achieve the same result in a round receive an identical ranking for the round.