BBO Daylong Tournament 1 - Apr 7, 2021 - Board 6

Board 6
Opponents vulnerable

♠ K J 7  ♥ J 8 7 4  ♦ K 7  ♣ Q J 9 4

RHO opens one diamond. I double. LHO bids one spade. Partner bids three clubs. That seems quite high enough to me, and the opponents agree.

	NORTH Phillip ♠ K J 7 ♥ J 8 7 4 ♦ K 7 ♣ Q J 9 4
	SOUTH Robot ♠ Q 9 2 ♥ 3 2 ♦ 10 9 3 2 ♣ A K 6 5

West	North	East	South
Robot	Phillip	Robot	Robot
1 ♦	Double	1 ♠	3 ♣
(All pass)

Glad to see partner isn't worried I'm one of those people who double one diamond without club support.

West leads the spade eight. This doesn't look promising. If trumps are three-two, then I can take four clubs, one ruff, two spades, and hopefully the diamond king. That's only eight tricks. If I go after ruffs before drawing trump, West will score a spade ruff.

What do I know about the high cards? East probably has the heart king, since West didn't lead one. He also has the spade ace. If he has the diamond ace as well, he might not have sold to three clubs undoubled. In addition, that would leave West with only 10 HCP. It seems likely the diamond ace is onside. 

I'm still not sure how I'm coming to nine tricks. But I might as well start by playing the spade jack to induce East to take his ace. He does. I play the deuce from my hand to leave open the possibility the West began with Q98 of spades. A careless falsecard of the nine would clarify the suit. At trick two, East shifts to the king of hearts. So East has ace of spades and king-queen of hearts. That leaves West with the heart ace and ace-queen-jack of diamonds. I play the deuce; West follows with the six. The five is still outstanding. East now leads the diamond eight.

This is a pretty friendly defense. Can I make this now? I need to score six trumps tricks without allowing the opponents to score a spade ruff. West will take his diamond ace and exit with his last spade. If I play a heart without drawing trumps, West will get a spade ruff. Perhaps I can draw two rounds of trumps, then play a heart, hoping West is out of trumps. That gives him 2452. No, that doesn't work. East will just win and play a third trump. But West will be under pressure, since he guards both red suits. Is there any way I can squeeze him? I don't have the entries for a traditional squeeze. But this looks like one of those entry-shifting matrices. Say I draw two rounds of trumps, cash the last spade, cash the diamond king, then play a heart. This will be the position with East on play:

	NORTH Phillip ♠ -- ♥ J 8 ♦ -- ♣ ? ?
	SOUTH Robot ♠ -- ♥ -- ♦ 10 9 ♣ ? ?

West holds two cards in each red suit. East must play a trump to stop the crossruff. If West pitches a heart, I win in dummy, ruff a heart, and dummy is high. If he pitches a diamond, I win in my hand, ruff a diamond, and my hand is high. What trumps do I keep to make it possible to choose which hand wins the trick? I need to hold 65 in my hand and honor-four in the dummy, and East's remaining trump must be the 2 or 3. That means I need to induce East to squander his club spots. Can I do that? Say he has 1032 of trumps. Maybe if I lead the 9 from dummy on the first round of clubs, he will think of some reason to cover.

I play the diamond deuce. West takes the ace and, surprisingly, does not play a spade. Instead, he cashes the heart ace, and East follows with the ten. Could the spade lead have been a singleton? West continues with the heart five. I see. West thought his partner had king doubleton of hearts. If that's the case, continuing spades would not work. He would need to give him a heart ruff instead. I play low; East plays the queen and I ruff. Now I don't need a second ruff. The heart jack is my ninth trick. I cash the club ace. When everyone follows, I claim.

	NORTH Phillip ♠ K J 7 ♥ J 8 7 4 ♦ K 7 ♣ Q J 9 4
WEST Robot ♠ 8 3 ♥ A 9 6 5 ♦ A Q J 6 5 ♣ 7 2		EAST Robot ♠ A 10 6 5 4 ♥ K Q 10 ♦ 8 4 ♣ 10 8 3
	SOUTH Robot ♠ Q 9 2 ♥ 3 2 ♦ 10 9 3 2 ♣ A K 6 5

East had 1083 of clubs. So if West had continued spades, I would have gone down unless East chose to play both his high clubs on the first two club tricks.

Thinking about this hand later, I revisited my thought "Maybe if I lead the 9 from dummy on the first round of clubs, he will think of some reason to cover [if he has 1032]." Is there a reason to cover? Here is the putative position at the point I lead the nine of clubs from dummy:

	NORTH Phillip ♠ 7 ♥ J 8 7 ♦ K ♣ Q J 9 4
WEST Robot ♠ -- ♥ A 9 5 ♦ Q J 6 5 ♣ 8 7		EAST Robot ♠ 10 6 5 ♥ Q 10 ♦ 4 ♣ 10 3 2
	SOUTH Robot ♠ Q ♥ 3 ♦ 10 9 3 ♣ A K 6 5

Indeed there is a reason to cover. If East doesn't cover the nine, I'm cold. I let the nine ride. Now I have two high trumps in dummy with which to ruff diamonds: king of diamonds, club to my ace, diamond ruff, spade to my queen, diamond ruff. If he doesn't cover, I can ruff two diamonds. If he does, I have an entry-shifting squeeze. Actually, I don't even need the squeeze, do I? If he covers, I can again just ruff two diamonds high, since the club six in my hand is good enough to draw the third round of trumps. (And if it wasn't, the squeeze wouldn't work anyway.)

But hold on. If I can make this contract by ruffing two diamonds high, maybe that's what I should be aiming for in the first place instead of looking for obscure squeezes. Why not just cash the diamond king, then play queen of clubs and a club to my ace. If West began with ten doubleton of clubs, then dummy's jack and nine are high and I can ruff two diamonds. Since this line works whenever West has ten doubleton of clubs and floating the nine works only when East has specifically 1032, this line is clearly better. Why didn't I see that at the time?

I think the problem is I was thinking about this hand as a crossruff. I need to duck a heart to set up the crossruff, so any line that didn't involve ducking a heart wasn't on my radar. Computers have an advantage over us in that they can simply try every possible line. We can't think fast enough to do that, so we play by identifying patterns: "This deal looks like a crossruff; this one looks like a dummy reversal; this looks like one of the deals where you have to do such-and-such." We have to think this way, but we run into problems when we apply the wrong pattern. When that happens, it is important to step back and ask yourself where your thinking went wrong. 

Why doesn't this hand fit the crossruff pattern? The reason to embark on a crossruff is insufficient entries. You need to score ruffs in your hand in order to ruff things in dummy. But entries aren't an issue here. I can use a club entry to ruff one diamond and a spade entry to ruff another. So there is no reason to duck a heart. Having discovered the "bug" in my thinking, perhaps I won't have this blind spot the next time.

That was disconcerting, though. Imagine having to explain to your teammates how you went down two in a cold contract by leading the nine from QJ9x opposite AKxx and passing it, letting West score his ten, followed by a spade ruff.

I score 97.8% for plus 110. That seems generous. I did nothing good; the opponents misdefended. And everyone has the same opponents, so this result shouldn't be that uncommon.

Why was it uncommon? For starters, not everyone doubled one diamond. Those who didn't usually wound up defending three diamonds, down one. Passing over one diamond is conservative. At this vulnerability, I would double with a little less. 

Of the eleven pairs who did double and reached three clubs, ten went down. Most declarers played a low spade from dummy at trick one, which is an error. You want East to win the ace to cut communication. Playing low makes it easy for him to insert the ten, which makes it easy for West to score his spade ruff later. 

The players who did play the jack at trick one fell from grace by falsecarding the nine from their hand, clarifying the suit for East. Accurate falsecarding isn't just a matter of playing gratuitous high cards. You need to consider the situation from your opponent's point of view and figure out how to create an ambiguity. The easiest way to do that is to ask yourself what cards you should retain rather than what card you should play. In this case, from East's point of view, West's eight could be from a singleton, eight doubleton, or Q98. You need to hold on to the cards you want East to think his partner might have, so you must retain your nine.

So it turns out I did do something good after all. Although 97.8% still seems like an excessive reward.