For nearly half a century the short club has been a familiar tool for opening bidders with balanced hands. It was the Four Aces in the 30's who introduced the idea of bidding a three-card club suit. This left a problem, however, with a hand containing a doubleton club, three diamonds and four cards in each major, and this became more acute with the growing trend to five-card majors.

The standard expert solution is to bid one diamond with such a hand. An alternative favored by some tournament players is to bid one club with a doubleton. This introduces an element of doubt when the opening is one club, but responder is on slightly firmer ground when the bid is one diamond, which will always be based on four or more cards.

This divergence led to a slam swing on the diagramed deal, from a regional knockout final last weekend in Halifax, Nova Scotia. At one table the North-South cards were held by Michael Kamil of Fort Lee, N.J., and John Suozzo of Teaneck, N.J., who were double winners in the tournament. They not only won the knockout event, together with Lenore Server and Leonard Karp of River Vale, N.J., but also had the highest score in both sessions of the master pairs, a rare achievement. A Little Trouble at the Start

The three-card diamond opening caused a little difficulty en route to six clubs, but North-South overcame it when Kamil decided to show delayed club support with his doubleton king. Since East had ventured an overcall in spades, West led the king of that suit. South won with the ace, drew trumps in four rounds and led a diamond to the king.

Without any clues, Suozzo might well have failed in his slam. But when he ruffed East's return of the spade queen he knew that East had begun with 10 black cards and West an equal number in the red suits. So there was no temptation to play East for the diamond jack, and he led his last trump, causing West great pain.

To keep his heart protection he bared the diamond jack, and South played heart winners followed by the diamond ace, taking the last trick with the diamond ten.

In the replay, North-South were using the very-short-club so North opened the proceedings in that fashion. It was now rather easier to reach six clubs, but North became the declarer. The lead was the singleton heart, and North made the normal play of the ten from dummy.

He would have had to look at all the cards to find either of the winning plays: taking the heart ace immediately and developing the same squeeze that Suozzo had found; or ducking a diamond at some point to take advantage of the doubleton king. NORTH (D) S A 9 4 2 H K Q 8 5 D Q 5 4 C K 7 WEST EAST S K 5 S Q 10 8 7 6 3 H J 9 7 4 3 2 H 6 D J 9 7 2 D K 6 C 4 C 10 8 6 2 SOUTH S J H A 10 D A 10 8 3 C A Q J 9 5 3 North and South were vulnerable. The bidding: North East South West 1 D 1 S 2 C Pass 2 H Pass 4 D Pass 5 C Pass 6 C Pass Pass Pass

West led the spade king.