phil_20686, on 2012-January-31, 15:40, said:
Yes but like all false cards you shouldnt make it all the time. If its automatic enough for us to be drawing inferences from it they should only be doing it sometimes...
While that statement is, I think, fair in general, there are types of falsecards that one should use all the time....so-called mandator falsecards.
For example, here is a well known one:
Dummy has AQ10x and declarer is known to hold 4 in the suit.....you hold J9xx in front of dummy.....declarer cashes the A and partner follows low. If you play low, declarer leads to his K and hooks your J. So you have to play the 9...now declarer can pick up Jxxx (assuming he has the 8) by cashing the Q....and you have created a stopper....this only works when you falsecard the 9....you have to do it all the time....you never gain when you don't.
I think this is in that category. I think there is no edge to ever not playing the K...the more frequently you falsecard, the closer to making declarer's choice a guess.
I got started on an attempt to show this mathematically and realized that I was far too ignorant of the math to even attempt. I suspect that I could have done this readily enough 40 years ago, but my engineering degree has sat unused for some 40 years, and my math skills, never great, have languished along with it.
'one of the great markers of the advance of human kindness is the howls you will hear from the Men of God' Johann Hari