ACBL Daylong 1 - Jul 29, 2021 - Board 4

Board 4
Both vulnerable

♠ 7 2  ♥ Q J 5  ♦ K 6 5 3  ♣ A K 7 5

LHO opens one diamond, and RHO bids one spade. I don't like passing with an opening bid, but I have no other sensible action. I pass. LHO raises to two spades and RHO goes on to four. I lead the club king and the following dummy appears.

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

West	North	East	South
Phillip	Robot	Robot	Robot
	1 ♦	Pass	1 ♠
Pass	2 ♠	Pass	4 ♠
(All pass)

Partner plays the deuce of clubs, and declarer plays the nine. It appears we have two club tricks and a diamond. There are fifteen high-card points outstanding, so there is room in partner's hand for the heart king. If he has it, I may need to switch to hearts before declarer can take a pitch--either pitching hearts from his hand on dummy's diamonds or pitching a heart from dummy on club tricks in his hand. 

While thinking in general terms like that is a good start, you should always construct a full layout before you make a decision. Sometimes what you are concerned about turns out to be implausible--or even impossible--for reasons that aren't clear until you have a complete construction. In constructing possible hands for South, I would normally assume he has at least five spades. But the robots in theory promise four spades with their two-spade raise, and they take that promise seriously enough to have no qualms about leaping to four spades with only four.

First let's construct a hand where declarer pitches his hearts on dummy's diamonds. How about

♠ Q J x x x  ♥ x x  ♦ A Q J  ♣ Q x x ?

Yes, that's perfectly possible. But there is no rush. I can afford to cash another club as long as I switch to a heart at trick three. Can I find a layout where dummy's hearts go on declarer's clubs? Perhaps

♠ Q J x x  ♥ x x  ♦ A Q J  ♣ Q 10 x x .

Now I have to switch to a heart at trick two. If I cash the club ace, it's too late. 

Next question. Are there hands where it costs to switch to a heart at trick two?  It will cost a heart trick if declarer has king third. But if the heart trick is going away anyway, it won't matter. So I need to find a hand where he has no discard. How about

♠ Q J x x  ♥ K x x  ♦ A Q J x  ♣ x x ?

Yes. A heart switch would not be a winner against that hand. Does the third heart even matter? Let's consider

♠ Q J x x x  ♥ K x  ♦ A Q J x  ♣ x x .

If I switch at trick two, I lose a club trick. But as long as I cash the club first, the heart trick I give away is immaterial.

At times like this, I wish my robot partner knew how to signal. Hearts is obviously the suit where our tricks might disappear. So he should play a discouraging club at trick one if he can stand a heart shift and an encouraging club if he can't. 

Opposite myself, I would shift to a heart at trick two after seeing the club deuce. But this partner's carding is no help, so I just have to go with the odds. The hand where I have to shift at trick two is rather specific. There are more cases where an immediate heart shift is wrong. So I'll go ahead and cash the club, then worry about what to do at trick three. 

I play the club ace, partner plays the three, and declarer ruffs with the spade nine. See how much time I saved by postponing my decision? Now I don't have to worry about what to do at trick three. 

Declarer wouldn't have bid one spade with 4-4-4-1, so he probably has five spades. His likeliest patterns are "5431" or "5521" with length in either red suit. Could he have longer diamonds, perhaps 4-3-5-1? Unfortunately I can't ask, but that would leave partner with a diamond void, so it's unlikely even if it's possible. For now, I'll assume declarer is 5-3-4-1, 5-4-3-1, or 5-5-2-1.

Declarer plays the eight of spades to the ace and the six of spades back to his queen, partner following with the five and jack. After seeing partner's spade jack, I'm pretty confident declarer has five spades. 

He plays a spade to dummy, presumably preparing to take a diamond finesse. Is there any reason for me to duck when he does? I don't see what it gains. And if he has ace-queen tight, ducking will not be a success.

On the third round of spades, I pitch the five of clubs; partner pitches the four of hearts. Here is the current position with the lead in dummy. Declarer has one low spade and seven red cards remaining.

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

Declarer plays the four of diamonds--seven--queen. Unless this is ace-queen tight, declarer must have the diamond jack. He would be finessing against partner's jack if he didn't have it himself. And he would be leading the ten and passing it with ace-queen-jack-fourth. So this is presumably ace-queen tight or ace-queen-jack tight.

I win the diamond king and return a diamond. Partner pitches a club. So I was wrong. Declarer had four diamonds. Now that I think of it, there is no actual reason to lead ten and pass it with ace-queen-jack fourth. It's just the instinctive play. But robots don't have instincts.

Not that it matters. I don't really care what declarer's red-suit shape is. I was just practicing. We still have a heart trick coming to us, so declarer makes four.

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

Taking all our tricks was worth 75%. Some defenders did switch to a heart either at trick two or after winning the diamond king, letting declarer make five. I can understand a shift at trick two. I think it's anti-percentage, but at least a plausible layout exists where it's necessary. If that's true for every play you make, you won't go terribly wrong. It's the plays that might lose and can't gain that you want to avoid. And shifting to a heart when you win the diamond king is a good example. Even if partner has the heart king, what does a heart shift accomplish? There is no reason to establish winners once the defense is out of entries. Unfortunately mistakes like this can be hard to notice, because we often get away with them. If partner has the king of hearts, you might never realize your shift was an error.

Concerning East's signal at trick one, there are some who play that a lead of the king asks for attitude and the lead of the ace asks for suit preference. That way, you can choose your lead from ace-king based on what signal you want partner to give. If I played that way, I would always lead the king. Why would I ever want a suit preference signal?

What I dislike about suit preference at trick one is it can create a headache if you don't wish to signal for either suit. In this particular case, you survive because you have a variety of clubs to choose from. If you play the four, partner can probably tells it's neither your highest nor your lowest, so he will get the message.

That's not always the case, however. Sometimes you have no middle card, or your middle card, from partner's perspective, could easily be your highest or your lowest. When that happens, partner will get the wrong message.

The problem is that suit preference creates a false dichotomy. Why is the choice necessarily between hearts and diamonds? Most of the time, it's clear what to switch to if a switch is called for, so the real choice is between "make that switch" and "try something else." What you want to see is a signal that unambiguously makes that distinction. In this case, diamonds is dummy's source of tricks. It is more likely that declarer will be able to pitch heart losers on dummy's diamonds than that he will be able to pitch diamond losers on dummy's hearts. So that is the concern the defense should focus on. Accordingly, you should play your lowest club if you have the king or queen of hearts and the highest spot you can afford if you don't (or the other way around if you prefer to signal upside-down). 

Since you never play a middle card, your card is almost certain to be readable. And the fact that you never play a middle card offers another advantage. It means partner can confidently place declarer with either all the spots lower or all the spots higher than the one you play, which may help him in constructing the full hand.

How does partner know what to do if you signal not to shift to hearts? He works it out as best he can, continuing clubs, shifting to diamonds, or playing a trump, depending on what would appear to work most often. Sometimes the best alternative is obvious; sometimes it isn't. But at least he knows that what is probably the most attractive defense isn't going to work. You've conveyed an important piece of information unambiguously. That often isn't true if your card is suit preference.