Weighed In The Balance… And Found Wanting

Board: 8. Dlr: West/None
	♠ 9 2 ♥ K 8 6 ♦ A J 4 3 2 ♣ J 10 2
♠ A Q 6 ♥ A 9 5 4 ♦ 10 6 ♣ A 6 4 3		♠ K 8 5 ♥ J 10 2 ♦ Q 7 ♣ K Q 9 8 5
	♠ J 10 7 4 3 ♥ Q 7 3 ♦ K 9 8 5 ♣ 7

The field did not distinguish itself here. A sizeable percentage bid to 3NT by West after a strongish no-trump. North of course led a low diamond - the two or three according to choice or system. Declarer of course put up the queen from the board, covered by the king and declarer's six (the ten would have been an interesting diversion --see below).

Now too many of the South player in the field took their eye off the ball, and failed to focus on the size of the minor spot-cards, the six that they had already seen, and dummy's seven. That being the case, if partner had four diamonds your play does not matter, and if your partner has a five-card suit to either the jack-ten or ace-jack-ten your play is equally immaterial. The key is that if declarer has either 106 (or less likely the J6) the suit will potentially be blocked. If you return the diamond nine to unblock the suit, you actually artificially create a blockage -- note partner's irritating 4 3 2 of diamonds. At an absurdly large number of tables 3NT was allowed to make on a diamond lead; (to be precise 3NT was declared 31 times on a diamond lead and made eight times out of 14 in the open series, six times out of eight in the women, and seven times out of nine in the seniors!).

Note the distraction I mentioned earlier; if declarer drops the ten on the first round of the suit he might have J10 doubleton and partner five to the A6. To avoid blocking the suit you must play back the nine, and when declarer follows with the six partner will not need to overtake. The position now becomes clear on the third round of diamonds.