South slipped in defense on this hand from the club Individual and lost a lot of match points. It is not usually correct to bid twice on a hand where you have pre-empted but with such extreme shape I don't think it would have been a terrible crime to have bid 5♠ over 5♦ on this hand. However against 5♦X a heart was led to the Ace and South ruffed the 9 of Hearts (suit preference signal for a Spade return) with her singleton diamond. Obviuosly not watching the card she had ruffed, South then played Ace and another Club to North's King. From North's point of view, this could be for only one reason. South had a second Diamond and wanted another ruff in Hearts!
Ooops! East won, drew trumps and the Spade loser went away for +500 only. This defence was correct only IF South had another Diamond.
What should have happened? How about :
1. Heart to Ace;
2. Heart 9 (lead a Spade!) ruffed;
3. 3 of Spades (lead a club back please) to Ace;
4. King of Clubs;
5. 3 of Clubs to Ace;
6. Club ruffed with 3 of Diamonds.
SIX tricks for the defence and +1100.
Various results on this hand where 12 tricks were available in 4♠ for +680 but some East/West pairs had been greedy and doubled this and 5♠ for losing 1050 and 1190 ! This is bad bridge. They have too many points in Diamonds and no tricks outside, which are needed to double contracts like this. The +500 was a "bottom" for North/South but +1100 should have been a next to top - they could not compete against 4♠X+2 (+1190).
Tip - Watch which card partner plays! It could be an essential SUIT PREFERENCE SIGNAL to help with Defense.