But a diamond loser was another matter: it might well be discarded on a heart winner.

Later, South discarded a diamond loser on the heart queen.

So, if East had played low, declarer would have discarded his diamond loser and got home.

You can now run the clubs to discard diamond losers.

If these break evenly he can throw his diamond loser and be sure of the slam.

In either case South would avoid the potential diamond loser and make his contract.

If South began with two diamonds he will still have a diamond loser.

East returned a club, and South kept control by discarding his diamond loser.

But he managed somehow to avoid a diamond loser and his result was identical.

East chose to spend his ace, and South could then avoid a diamond loser.