I cashed two top diamonds before switching to the ♥8. Declarer cashed the king of trumps and I played the 9. Now if the 9 is a true card, it can only be from singleton 9 or Q 9. As he cannot pick up Q x x x with East, Declarer played the ace next. It would be nice to report that I had played a Zia-esque 9 from 9 x and fooled declarer into going down in an easy contract, but I only had the 9. You can't false-card with a singleton.
A former world champion was sitting dummy, and as she pointed out in the nicest possible way, declarer misplayed the hand. He should have taken a first round finesse in trumps. This loses if I have a singleton queen of trumps, but gains when I have a small singleton, which is four times as likely.
The second hand came up the following day in the National Pairs regional final. By strange coincidence, the world champion was again sitting on my left.
Declarer ducked the opening spade lead, won the second round in dummy and led a club on which East played the 8 (playing normal count signals). Now what? One option is to the finesse the 10, but that is putting all your eggs in one basket and so declarer played the queen. West won and cleared the spades. Trusting my ♣8 as an honest card, declarer now cashed the ♣K, hoping that I held J 8 doubleton. This was not a success and the contract drifted two off.
So why did I find that devious ♣8 that led declarer astray? I have to admit that it was an auto-pilot Smith peter to confirm interest in spades - totally unnecessary of course as the spade position was an open book. It's better to be lucky than good.
