South won in his hand and played a spade to the jack.

East won with the king and played a third spade, a clear error.

But would he have done better to play a spade a trick earlier?

Perhaps the best line is to take the trick on the board and play a spade to the jack.

There was no hurry to play spades, so he called for a low heart.

When he played a spade to his king, West won with the ace and returned the ten.

A heart finesse lost to the king, and West should have played a third spade.

The group was too large to play spades, so they'd settled on poker.

He led to the heart ace, collecting the king, and played spades.

He played a spade to the ace and a club to the queen.