East probably has a singleton and will score a ruff.

West produced the club queen, and scored a third-round ruff.

A low club would have been decisive, scoring a quick ruff, but West had no reason to know that.

This was covered by the king and East scored a second ruff.

Instead he won with the ace and returned the jack, scoring a ruff on the third round to defeat the game.

Now there was no way for the defense to score a ruff.

If he won with the ace and played diamonds, West would be able to score a ruff.

West could have led his singleton spade to score a ruff, but did not choose that course.

As it turned out, South did score a ruff, but it was not the one you might expect.

East was tempted to return a spade, scoring a quick ruff.