Drawing inferences from the bidding is routine for an expert. In was of vital importance in Round 9 of the Rosenblum:
North led the [C]K and declarer ruffed in dummy and played a spade to the king. When it held he played the [H]6 and ran it! He knew from the bidding that North held a balanced hand, and he needed three rounds of hearts to stand up. When the six held declarer ruffed a club and played hearts, pitching his last club from hand. North ruffed and played a diamond but declarer could win in dummy, cash another diamond, ruff a diamond and play the [S]Q for a seemingly effortless +450.
No doubt you have spotted North’s mistake.
He should win the first spade and return the [S]10, pinning dummy’s nine.
The initial play was identical, North again making the mistake of ducking the first spade. Here declarer continued by ruffing a second club and he then played three rounds of diamonds, ruffing. So far so good, but declarer then made the mistake of exiting with a club (I winder did he pull out the wrong jack?) and he finished two down.
Looking at three small clubs, East knew there was a good chance his partner would be void.
South led the [S]K and switched to his trump, but declarer won, cashed the top diamonds and claimed when the queen appeared. Only eight pairs reached 6[H] – three lucky ones were doubled.
There was no inference to be draw here, so Mossop had 13 IMPs.
