NORTH 432 JT2 AQT82 A2 QJ96 97 J765 JT9 KT87 AK6 K4 K876   A5 Q8543 93 Q543

Dealer: South    Vul: Both   MP Scoring West Pass Pass Pass North Pass X 1 Pass East 1N Pass Pass South Pass Pass 2

West led fourth best spade, East inserted the K and declarer allowed it to win.
East led a small heart won by dummy's T.
The A provided a means back to hand.

Estimating points around the table, declarer added dummy's 11 to 8 in hand.
Of the defence's 21 points, East's 1N had advertised 15 to 17.
That left West with an estimated 4 to 6 points.
If East West were using standard plays for third hand, East's play of the K denied the Q, then with West.
By subtraction then, West had unknown remaining points ranging 2 to 4.
The outstanding point cards included:
J AK KJ KJ
Which combinations of those might West hold ranging in points from 2 to 4?
Two jacks? A king? Three jacks? A king and a jack?

Declarer led the 9 and East won the K.
West then was 'marked' with the J and a remaining range of 1 to 3 points.

East returned a spade and declarer ruffed in hand.

Dummy's T was successfully finessed and diamond continued, East twice discarding.
A dummy heart was led and East cashed the AK.
East's spade continuation was ruffed and in dummy remained the A and established fifth diamond.

On this occasion, North's reopening double payed good dividends:

   7>     9-    2-    4     7-                                              5      -    2-   11     9-    7-     -    6 
         140  -110  -100   100   ----  ----  ----  ----  ----  ----  ----   80  -140  -110   200   140   100  -140    90