West did not see that it was vital for him to play the queen, and played low.

Now he could play the queen with an extra chance.

Playing the queen would have been an error if South held the ace, with or without the jack.

But how did he know that his partner would not be forced to play the queen or jack under the king?

He led the heart nine, and played the queen on East's jack.

In the actual position, South had to play the queen.

"In general it is right to play the queen," was the cautious answer.

"If I lead the 10, my partner knows looking at the dummy hand not to play the queen."

South could not afford to play the queen, so he played low, and the 10 won.

If the ten loses to the ace, you next play the queen.