Sometimes a hand is bid in bridge to a level, which was never desirable in the first place by the bidders, but is yet inevitably bid because the opponents keep sacrificing in the long suit or fit, which takes the level of bidding soaring upwards sometimes to the farthest limits to outscore the opponents.
In our hand under analysis today something like the above happened during the bidding which took, north south to the dizzying heights of bidding the grand slam in spades with one ace and two kings missing - a poorly bid grand slam that as the cards reveal has at first very little chance to succeed.
The hand first along with the bidding is as follows: As you can see from the bidding, it is an excellent little slam to bid with 12 top tricks, which north judged well to leap to 6S, after west's 4C preempt on his partner's 1S opening. But east muddied the waters by bidding a sacrificial 7C since NS were vulnerable whereas EW were not. As the card lie, the opponents are losing 2 hearts and 2 diamonds for 800 as against 1430 little slam vulnerable for a net game of 630. But when north pushed on to the grand slam of 7S, south had a real problem to find the 13th trick. For as the cards lie, he has 8 trump tricks, 3 heart tricks and 1 diamond trick for a tally of 12. From where can he extract the vital 13th trick for the stakes are pretty high as there is a grand slam on the taking or failing.
Of course in bridge, grand slam are not bid without a 95 percent chance of making it as the arithmetic of a loss in case the grand fails when a sure little slam was on is tremendous. But here north has taken the plunge and south was in icy waters the moment he saw the dummy on the KC lead from west against 7S contract to be played by south.
As south viewed his chances, he could only admire the opponents for pushing them into what seemed a very dicey grand slam that had very little chance to succeed. But fortune favours the brave. And our declarer was none other than the great Italian legend of bridge, Georgio BellaDouna who was known for his remarkable play and defence in bridge, which had made him win the worlds highest championship - the 'Bermuda Bowl Umpteen Times.'
The Italian expert weighed his chances in making the grand slam to rest on some sort of a squeeze. The squeeze play is the most difficult in bridge if it is not a just a simple one whereby the opponents get squeezed on the simple run of cards quite automatically without much fuss and fret.
But here, the bidding revealed that perhaps this was a squeeze of subtle variation and not a simple one against anyone opponent. West's 4C preempt made it most unlikely that west held the heart length and east the shortage. Giving the pre-emptor the AK of clubs 7 times the likelihood of both diamond honours with west was out of question. If east held both, along with the heart length, there was of course a very simple red suit squeeze working.
But as you can see from the lie of the cards that this was not the case. Lets first imagine what would happen if east held both diamond honours. Then after ruffling the first club in dummy when you run 6 more trumps, leaving 6 cards with east, he will be squeezed in the red suits. Down to KQ of diamonds if he retains his 4 hearts, on the last trump he will be forced to either unguard the diamonds or the hearts. But BellaDonna catered to the more likely distribution to be a diamond split honours between east and west, and in that case, he reasoned that he would have to rely on a guard squeeze against both opponents.
So that when the last trump is poised for play the position is as under: As you can see, south had laid the solid foundation of a guard squeeze. The key play lay in unblocking diamonds from hand by discarding both the J and 10 of diamonds and still retaining 4 of clubs. You may have also done so, but would you have still retained the 4C as south did?
For it was very necessary to keep the threat card of 4C so that the opponents are pressurised in holding on to one club honour. Now lets see the beauty of the guard squeeze. On the last trump, if east parts with the club queen, you discard 3 of hearts from hand and west throws 8H. But when you play 3 rounds of hearts next, west is now caught in a minor suit squeeze per force holding AC to bare his QD for you to run the diamonds. East is no better placed even if he throws KD instead of QC. Again south discards a heart from hand, and after cashing the hearts takes a simple finesse against west's Q of diamonds as his only chance to bring home the well played grand slam by Belladonnna.

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North         West      East      South
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QJ986432        -         5       AK107
A4             108     J9752       KQ63
A93           Q842       K76       J105
-         AKJ10865      Q973         42
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The Bidding:
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South     West    North     East
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1S         4C      6S         7C
Pass     Pass      75   All pass
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