doubleton

And as the club two had been played, the seven could not be the top of a doubleton.

If it was not, South held a doubleton and no harm would be done.

Holding a doubleton, he would have played the higher card.

Here each doubleton is worth one point, giving North a total of nine.

If South has a doubleton ace it will make no difference.

The chance of landing in a 4-2 fit because East has a doubleton is quite small.

And if East had the doubleton diamond king, this would have been the only winning defense.

The doubleton eight with West is twice as likely.

This was artificial, showing a hand with a weak doubleton.

Playing the king at once would lose if East began with a small doubleton or singleton.

He considered trying to drop a doubleton queen, but that would have failed.

West's lead of the club nine was sure to be a singleton or a doubleton.

Had West made a tricky and unlikely lead from a doubleton queen?

South knew the club jack was on his left, since the Polish style is to lead low with a doubleton.

The queen would have been the winner against an original doubleton nine with East.

His nine should have indicated a singleton or a doubleton.

As South, you decide to lead a low club, hoping for a doubleton honor on your left.

With a ten-nine doubleton, he might well have played the ten.

And holding a small doubleton, Cohen might have scraped up some response.

And it would be essential if South held a doubleton 10 of spades.

In this way he would have made his doubled game if West had held a doubleton club queen.

This play works when East has a doubleton ten or jack, without any need for a defensive error.

This was a safe way to guard against the possibility of a doubleton queen in the West hand.

Along with his known doubleton club, that left only three major-suit cards.

The fall of the spade 10 doubleton is helpful in this variation.