BBO Daylong Tournament 1 - Jun 1, 2021 - Board 3

Board 3
Their side vulnerable

♠ Q 9  ♥ A J 10 3  ♦ K 5 2  ♣ A Q 3 2

I open one notrump in first seat. Partner transfers to spades and bids three notrump, which I pass. West leads the four of diamonds

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

West	North	East	South
Robot	Robot	Robot	Phillip
			1 NT
Pass	2 ♥	Pass	2 ♠
Pass	3 NT	(All pass)

The diamond three is missing. So the lead could be fourth best from a five-card suit or lowest from a three- or four-card suit. Less likely (though not so unlikely as against humans), it could be from shortness.

I have seven top tricks. I can try to develop two more in spades with the club finesse in reserve if that fails. The percentage play in spades is to lead a spade to the nine. If spades are three-three, it's a toss-up which hand to finesse for the jack. If the suit is four-two, however, you must hope for jack doubleton on your right.

But the threat of losing three diamonds tricks and two spade tricks means the percentage play in spades isn't the only consideration. I must also worry about tempo. I would like to lose the lead only once, or, failing that, lose the lead the second time to the hand with only three diamonds. At this point, that hand is more likely to be East. If I lead a spade to queen. I may be able to finesse West for the spade jack later, not caring whether the finesse wins or loses. 

There are other advantages to this line as well. If I lead a spade to the nine and it loses to the jack, I still have only seven tricks. If I lead a spade to the queen, I'll have eight. Once I have eight tricks in the bag, I have a variety of ways to go after trick nine. I can finesse the spade. I can finesse the club. Or I can try for some kind of end play. It all depends on my read of the hand. As Reese once pointed out, having eight cashing tricks in three notrump leaves you in a strong position. There is almost always some way to find a ninth.

I play the diamond ace, East plays the six, and I play the five. (Better than the deuce, which might clarify the diamond count for East.) I still haven't seen the three.

I lead the spade three--deuce--queen--ace. With some holdings, West might have ducked to retain his entry. I need to keep that in mind in case I have to guess the end position. But I must also keep in mind that the robots will duck less often than human experts. They won't duck if it might lose double dummy (for example, with ace-empty third), whereas a human expert might, assuming that you are unlikely to continue with a low spade to the king.

West continues with the nine of diamonds and East plays the ten. It's still not 100% clear who, if anyone, has five diamonds. The four might have been from a five-card suit, or it might also have been lowest from 984. Although that would give East QJ1063, and he might have played the queen at trick one from that holding. In any event, I need to duck this. If they continue diamonds, I'll make my final assessment of who is more likely to have five. If I think it's West, I can safely finesse in spades. If I think it's East, I may decide to play on clubs

I duck. East continues with the diamond jack. I win with the king, and West plays the queen. The eight was the right play, silly robot. I know you didn't block the suit by continuing the nine from Q94. So I now know that if anyone has five diamonds, it's you. That means it's safe for me to take the spade finesse.

I pitch the club six from dummy and lead the nine of spades--seven--four--eight. I play a heart to dummy and cash the spade king. Everyone follows, and I claim.

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

Plus 660 is worth 78%. Some went down by leading a spade to the nine at trick two. We've already discussed why that line is wrong. Others held themselves to four by ducking the first diamond in both hands. Since the four can't be from a six-card suit, there is no reason to do that. Those who did duck the first round got a club shift from East at trick two. When they ducked this to West's jack, they could no longer score eleven tricks. 

One person made six. Obviously you can. Knock out the spade ace as I did, then win the the second diamond, run the spades, and take a club finesse at the end. I have to admit I didn't even consider that line. But if I had, I would have rejected it. Risking the contract in hope of finding a three-three break with two finesses working doesn't seem like a good idea. I checked the hand records to see if declarer had reason to believe this was going to work. It turns out he won the opening diamond lead with the king in his hand. After that, the play was perfectly reasonable. Having lost the option to duck the second diamond, you sort of fall into making six.