This deal from the second round appeared to be a bidding test for EW, but at the table I was watching, it also proved to be a defensive problem:
1} 1+, natural or 12‐14 balanced or 18‐19 balanced or any 1444 (15points can contain 5)
South led the 2 and declarer took North’s king with the ace and played three rounds of hearts ending in dummy. Had the suit divided she would have tried for four tricks in spades. When South discarded on the third round declarer played the K and South won and played the 4 for two down.
2 18-19 NT or any game force (not )
2 Transfer to 2NT
For the second time 6 was never in the picture.
South led the 4 and declarer won with the ace and played a diamond to the king. When it held she continued with the queen of diamonds dropping the jack and North pitched the 8. When South ducked for a second time declarer changed tack, cashing the top spades, finishing with ten tricks.
I can’t explain why South ducked the second diamond (her partner could hardly have an ace in addition to the K) but could North have done anything to make things even easier?
Assuming the club lead promises an honour, North knows that the defenders can cash four tricks as soon as they get the lead. To alert South to that, maybe North should discard the Q! That should make it clear to South that she should grab the A and play clubs.