hey bub, watch where you're going. i mean, welcome to BrainDen. get your point, should have probably stated she shuffled the deck. this puzzle was kinda a continuation of a previous one so one could presume the deck to have been previously used.
all true, save for that last bit. had figured this to be the logical starting point
hello Assassin.MTS - ah yes, you've pointed out the dilemna quite well and welcome to the Den.
and @ augustinus - welcome to you as well. had originally intended only black and red as responses but am curious as to your method mentioned above.
sorry to have apparently abandoned this thread. have had a tough end of the week. didnt quote WoS above and am still working out Phil's extension of your reply. when first working out this puzzle, seemed to think that in the worst case, a comprehensive binary reduction would still take 26 trials. am rethinking/still thinking. and at EventHorizon, not a programmer but hope to try to follow your code to hopefully gain some insight into how that works.
maybe should have worded the question differently and asked for descriptions of methods that did better than 27 trials rather than asking for the minimum number of trials. probably still would have gotten to this same place fairly quickly - i.e. in way over my head.