In this symmetric deal, nine tricks can be made in notrump by any declarer.

Given the symmetry of the deal, we only need to analyze one declarer, so we pick south as declarer just for consistency.

Fundamentally, the problem for the defense is that even though they can set up either diamonds or clubs with one lead of the suit, the suits are blocked, and there is no immediate entry to the suit that is set up.

Isn't declarer similarly blocked? Yes. But look what happens to the deal when west leads a low club. North pitches a spade, and south wins the trick in his hand, then leads a low spade to the ten, east winning the jack, leading to: East/west's clubs are blocked, and west at the moment has no entry. What does east lead here? When north/south get back in, they have seven spades and the , along with the in the first trick. But at this point the defense can only take two clubs and the diamond ace before surrendering the lead.

But what if west leads a diamond? Then north covers, and, whatever east does, south pitches a heart. Now, south only needs to lose one heart to take seven heart tricks, plus a diamond and a spade.

Finally, if west leads a heart, he lets east pitch a club to begin an unblock, but he does nothing to set up any of his own suits. Instead, he has blown his heart stop. Declarer just wins three hearts and plays a low spade to the ten, and east is forced to win, leading to this position: Whatever east/west pitch on the three hearts and a spade, all they can take when east gets in is their diamond and club aces, and then when declarer gets back in, he takes the and five hearts, along with the first three hearts [if the defense takes the , north must pitch a heart, but then south's becomes good.]

What is happening here?

Each side has two suits they might try to set up. In order to set up and run a suit, they need to lose a trick in the suit, and then either pitch a card from the holding to unblock the suit, or lose the lead again to set up an entry to the long suit to make up for the blockage.

Now, when west leads a club, he does the first step - losing the mandatory club trick. But the club also lets north pitch a spade, so both sides take a step towards their respective goals. When north leads a spade to lose to east, west gets to pitch, but he holds the . So he can make a step towards establishing diamonds, but that does not continue establishing the clubs. So east/west have taken one step towards establishing diamonds and one step towards establishing clubs, while north/south have taken the two steps needed to establish spades.

Comments

I have computed double-dummy results for about 930,000 symmetric deals out of 16,777,216 different symmetric deals, systematically choosing good "representatives." [Basically, if you have a symmetric deal, you can get to one of my representatives by swapping around spots smaller than the eight. ]

Of these deals, this is the only one where each side can make nine tricks. In fact, it is the only one that can make more than seven tricks. Is this deal unique? I can't claim that at this moment, but I would not be surprised if it was.