[bluecalm]

This time it's not me playing but a top player:

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This is Gazilli auction. 2♦ is relay 8+hcp and I think 2♥ followed by 2NT is 5-3-3-2 but really I am not sure how that stuff works (and unfortunately it could be important for the play). Anyway, to the play. Opponents lead 3/5 and then play attitude.

1: 5♣, 9♣, A♣, A♣
2: 2♥, 5♥, 7♥, A♥
3: 2♠, 7♠, ?

Clearly our hope is 5 spade tricks. Do you read into lead sequence or just go with the odds (and whats "odds" are in that case is interesting question too) ?
It's decision time !

[gnasher]

[Duplicate]

[gnasher]

I'll assume that 3♣ and 3♠ were natural and the other suit bids were relays.

It looks like clubs are 4-3 one way or the other, and hearts are Hx=HHxxx. LHO didn't lead a diamond, so he won't have five of them, and three is more likely than four.

LHO can have three spades only if he's 3244, but he might have led a diamond from that. His most likely shape (of the ones that are relevant) is 4234, so I play ♠10.

[bluecalm]

I think 3♣ - 3♠ are relay and 5-3-3-2 with 3 hearts but those Italians, they won't publish their systems

[rogerclee]

To me the most likely cause of this defense is that clubs are just 6-1 (LHO led the 5 from 865432), since it is so hard to construct hands where RHO would shift to a heart, possibly away from the queen, when he had Axx of clubs. That said, we are down 3 if we are wrong about the spades, but I will play the ten anyway.

[rhm]

rogerclee, on 2012-January-08, 07:48, said:

To me the most likely cause of this defense is that clubs are just 6-1 (LHO led the 5 from 865432), since it is so hard to construct hands where RHO would shift to a heart, possibly away from the queen, when he had Axx of clubs. That said, we are down 3 if we are wrong about the spades, but I will play the ten anyway.

I am not convinced about this. East can probably see when you drop an honor under his ace that this lead might be from 4, which is more likely than six, and that declarer holds KQJ or KQJx (and therefore little else in HCP.)
Attacking dummy's entries looks also not unusual to me.

Playing for spades to be 3-3 is a priori about 36%, finessing the ♠J about 42%.
But if clubs are 4-3 or 3-4 the spade break goes up for a number of reasons (among others heart lead was not attractive to West) and it gets closer.
The deciding factor for me is indeed that finessing risks minus 300, while playing for the drop is likely to be only minus 100 if wrong.
Say there is no winning decision in spades (♠J with West and ♠s do not break), you suddenly have given up 5 IMPs for nothing.
This difference is enough for me to take the slightly lesser chance.

Play the ♠Q and for the drop.

Rainer Herrmann

[rogerclee]

rhm, on 2012-January-08, 08:49, said:

I am not convinced about this. East can probably see when you drop an honor under his ace that this lead might be from 4, which is more likely than six, and that declarer holds KQJ or KQJx (and therefore little else in HCP.)
Attacking dummy's entries looks also not unusual to me.

RHO's heart shift is dangerous no matter what he shifted from, certainly more dangerous than continuing Axx of clubs. If he underled the Q, then it could give us a no-play contract a lot of the time, and if he underled JT or J/T I don't see anywhere where it says we can't have Qx Q9xx KJxx Jxx (presumably we played the jack at trick 1).

Edit: If all we know is clubs are 6-1 and we assume that if the spade hook loses that they will always play back a heart, then the Pavlicek suit calculator says

Spades 3-3 28.38%: Hook has EV of -6 imps
Spades 4-2 8.51%: Hook has EV of +0.67 imps
Spades 2-4 38.31%: Hook has EV of +6.3 imps
Spades 5-1 0.93%: Hook has EV of -5 imps
Spades 1-5 20.43%: Hook has EV of +1.67 imps
Spades 0-6 3.41%: Hook has EV of +3 imps
Spades 6-0 0.03%: null

Hooking has +1.165 imps EV. This is less than I thought intuitively, but the more I think about it the more I think clubs are 6-1.

[bluecalm]

Full hand:

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Madala played spade to the T and scored the game. 2♠ was the contract in the other room.

I don't have much to add besides that maybe one reason for a switch is that E thinks he stops ♠ and has one more entry to his ♥ suit.
Unfortunately some clues might be in the bidding but I can't offer full explanation. I thought the hand is interesting on its own even if we miss some vital bidding clue.

Quote

Pavlicek suit calculator

Link ?

[cherdano]

Did LHO falsecard or do they not play 3/5 leads against NT?

[bluecalm]

cherdano, on 2012-January-09, 06:16, said:

Did LHO falsecard or do they not play 3/5 leads against NT?

I screw up in OP
I somehow remembered the lead was 4♣ and then when copying the play I didn't notice it was actually 5♣.
According to their cc which I see now, they lead 2th spot from xxxx and 4th from honors. Sorry for confusion.