we play NICE here, British....
To truly test ninjatude, one must devise some set way of quantifying points. Get a large cloak, and walk into a crowded gun-friendly location (a range, store, whatever), looking like a bulky Sith-lord. When all eyes set on you, discard the cloak (or if the fates would have it, a calm, cold wind will genly rip it from you, revealing you in all your tacti-ninja might). If you have ninjatude of ANY level, people (women, men and children) should be SWOONING left and right. Those with more tactical fortitude should at least be rendered stunned and speechless.
Assign points for each swooned, stunned, and cowering individual. Add bonus points if you develop some sort of cult-following, i.e. ninja-groupies (an extra bonus for each female ninja-groupie). Remember, dramaticism would help in the robe-discard phase.
To keep it fair: y'all should both go to the same place, same number of people, but a different day (to let them recover from post-ninja-exposure trauma).