In yesterday's deal, several robot defenders at Bridge Base Online surprised us by failing to send an accurate suit-preference signal when giving partner a ruff. This was the very next deal, played 16 times.
Every auction started as given, two spades being a Michaels Cue-Bid, showing at least 5-5 in hearts and either minor. The mystery is why 15 Easts passed out four spades? Yes, they had two aces for defense, but they had a great fit with partner. They should have bid five hearts, where they would take six hearts, one diamond, one club and three ruffs on the board.
At three tables, West led a high heart. South ruffed, drew trumps and played on diamonds. Although East held up his ace until the fourth round, declarer lost only one diamond and two clubs.
At the other 13 tables, West was psychic, leading a club. East won with the ace and cashed the diamond ace to get the news. Now 10 Easts returned the diamond nine, a suit-preference signal for hearts! The Wests ruffed and tried to cash the heart king.
Two Easts led the diamond eight, and each West continued with the heart king.
One East robot did everything right. It bid five hearts, after which South went five spades, and West doubled. East won the club lead, cashed the diamond ace and continued with the diamond seven. West ruffed and returned a club, so the contract went down four, minus 1,100, after two aces and five ruffs.