A First Example

If North/South declare notrump, the defense starts with hearts, killing the entry to the North hand before the spades are established. South gets one spade, one heart, three diamonds and, with care, a club.

If East/West declare notrump, the defense starts with spades, which establishes three spade tricks before the heart entry to North is killed. North/South get three spades, a heart, two diamonds and either another diamond or a club.

If East/West declare spades, the defense starts with trumps. West can duck the ♠ A as many times as he wants, he still cannot get to East's hand before North gets in again to finish pulling trumps. North/South get three spades, a heart, two diamonds, and an eventual club.

If North/South declare spades, West leads a low heart and East gets to ruff a heart when West wins the second round of trumps.

Hearts

If North/South declare hearts, a heart lead keeps them from scoring any extra trumps, and they are left with three spades, one trump, and two diamonds.

If East/West declare in hearts, the defenders start by attacking spades while North still has a heart entry. When North gets in with a heart, North runs spades and West is forced to overruff South on the fourth round, and North gets another heart, for two spades, two hearts two diamonds and, eventually, a club.

If declared by North/South, the defense starts with (low) heart leads. This allows the defense to get two heart tricks and killing declarer's entry to the long spades. That means that North/South loses a diamond, two hearts, a spade, two clubs and either a third heart or, when South ruffs the third heart, a second diamond.

If declared by East/West, South takes two top diamonds before attacking spades. West wins the second one, and plays ace and a heart, the king winning in dummy. Another two spades are led, pitching a heart and a club. Then the club jack is led. East has to cover, South plays the king, and West wins the ace and is caught in an endplay:

There is no way to prevent North/South from scoring two tricks.

If West leads a high heart, and East pitches a club, South ruffs low and exits in clubs to West's hand. West, force to exit in clubs or hearts, must allow South to ruff with the nine in dummy or eight in hand, respectively, unless East ruffs high. Either way, North/South must score one of their two remaining trumps. Twist and turn as they might, East/West can't keep North/South from scoring two more tricks, for two spades, the heart king, two top diamonds and two more tricks.

If declared by East/West in clubs, the defense starts with spades. Eventually, South gets to pitch a losing heart on a spade. South then takes two top diamonds and exits in diamonds to this situation:

East, stuck on lead, can't avoid two more losers. Say they lead a club to the ace, and a club back to the jack, queen, and king. South simply continues with a high diamond, and West is forced to ruff and South scores a long trump.

If declared by North/South, the defense starts with low hearts, which has the usual entry-killing effect. North wins the first heart, then attacks spades. West wins the second spade, leads a low heart to East, who then leads a club to West's ace and a club. West cashes a heart and leads a low club to the jack, queen and king.

East/West have taken two hearts, a spade and a club, and they will get a diamond and two more clubs.

This is a rare par-zero deal of complexity three. The spade suit is the only par-zero suit:

South can make exactly six tricks in any contract.