Source: 
Daily Bulletin; 24th BERMUDA BOWL. Rio de Janeiro, Brazil October 17, 1979
It is quite surprising how many deals there are where, as a defender, you should endeavor to count declarer’s hand. If you count you find good defenses and get good results. If you don’t count, you make costly blunders, and there is weeping and wailing and gnashing of teeth.
In the third round-robin, Jim Borin and Barbosa both got to 6
doubled on this sequence:
 J 10 9 7 5 J 2 J 7 6 4 6 4 |
||
| 8 3 9 8 6 4 K Q 10 9 3 J 3 |
A K Q 10 7 5 5 A Q 9 8 5 2 |
|
| A K Q 6 4 2 3 A 8 2 K 10 7 |
||
| South | West | North | East |
| Calvo | N. Borin | Dhers | J. Borin |
| 1 |
Pass | 1 |
4 |
| 4 |
5 |
5 |
6 |
| Pass | Pass | Dbl | The End |
When Barbosa was East against Far East, 6 was doubled by South rather than North.
Calvo led the K and declarer laid down the A-K. The slam he thought was likely to depend on the club finesse. However when Borin now led the 5, Calvo rose with the A and played a club. Curtains!!!
South should count declarer’s winners: six hearts, the A, and at most four diamond tricks!
At Barbosa’s table the interesting point is that declarer did not give South a chance to make a reliable a calculation.. On ruffing the spade opening Barbosa led a diamond straight away.
It is hard to see what Kuo, South, could gain by ‘ducking’ as he did. But at any rate Kuo could plead that he did not know absolutely definitely and beyond any shadow of a doubt that he could beat the slam! by rising with the ace and returning either a spade, a heart or a diamond.