Blockage

This is the first part-score deal of this collection. Of course, given the North/South hands, nobody will end up in a part-score, but no game makes, double dummy.

In the unlikely event that South is declarer in hearts, South can only make eight tricks on a diamond lead. There is no time to find a discard for the second diamond loser, and it is impossible to avoid two trump losers, two diamond losers, and a club loser.

However, when declared by North, West only gets to lead diamonds once, when in with the ♣ A. Declarer can eliminate clubs and spades from East's hand then throw East in with trumps to give up a second diamond trick at the end.

In the unlikely event that North declares a spade contract, he can take at most eight tricks. East leads a spade on opening lead, and when West gets in with the ♣ A, West also leads a spade. This kills declarer's chance to ruff a club in dummy, and the North is left with four spade tricks, two hearts, a diamond, and a club.

With South declaring spades, West might try a diamond lead. East has to duck or he gives declarer a second diamond trick, and South wins the ♦ K in hand.

South cannot afford to try to set up the club ruff immediate. Instead, he takes the top hearts, pitching a diamond from hand, and then leads the ♣ K at this position: Should West win the first club? If he wins it, what suit does he exit in?

If West exits a trump, declarer wins in dummy, cashes the second club and exits a low diamond from dummy.

If East does not fly the ♦ A, West must win. Caught on lead at this position: West can't lead a club. A diamond lead gives declare an entry for a club ruff. And a spade lead gives declarer an extra spade trick. West cannot avoid letting declarer make four of the six remaining tricks.

So maybe East should have flown the ♦ A when the low diamond was led off dummy? After all, while this sets up the ♦ Q, there is no remaining entry to use it.

But what does East exit with after flying the ♦ A?

If East leads a trump, declarer cashes two top trumps then throws West in with a third trump. West can cash the ♣ J, but then must give declare a minor suit winner, either the ♣ 10 in hand or the ♦ Q in dummy. If East leads the ♥ Q declarer ruffs high, ruffs the club, then leads the good ♦ Q off dummy, pitching his last club. West can ruff it (if he pitched his diamond) or not. Either way, he is endplayed into leading to declarers ♠ K-J in the end-position.

So, let's step back one more step, to when West won the first club and exited a trump. What if, after winning the club, he exits a club? Declarer wins in dummy and leads a low diamond. If West wins, he is again stuck, so East must fly the ♦ A, as before. But here the ♠ 10 remains in dummy as a potential entry to that good diamond, giving declarer his ninth trick again.

Lastly, what happens if West exits a diamond? Declarer plays low, and the blockage in diamonds has its affect again. East can overtake, but has no satisfying shift, while if West is left on lead, he cannot prevent declarer from ruffing a club in dummy.

West also cannot profit from holding up the club one round - the blockage in diamonds is firmly around his neck.

The diamond suit blockage here is crucial. It does not keep the defense from taking the two diamond tricks which are rightfully theirs, but it does allow South to dictate who takes the second diamond trick, and, since the ♦ A is East's only entry, it gives declarer the tempo to set up a club ruff.