Another Defensive Hand from the Software DEFENSE
By Mike Lawrence

If you returned a diamond, you set two hearts one trick. If you tried to cash the ace of spades, minus 110.

The winning play is a diamond but the reasoning is what counts here.

Count declarer's winners. He has four heart tricks. He has three diamond tricks.

Your partner's queen of clubs suggests he has the jack as well. If East started with three clubs to the queen, that would leave South with six of them, a most unlikely holding.

This means that if you return a diamond, South will have only seven tricks. After taking his diamonds and his heart, you will get the last trick with your ace of spades or your partner's jack of clubs.

This is a nasty hand because the illusion is that declarer has lots of winning tricks. Only if you count them will you see he is short one winner.

Just for the record, East was a wimp during the bidding. He had an easy two club bid. Not that this would have affected the bidding greatly, but East's pass is symptomatic of someone who is being too conservative.