[pescetom]

A problem similar to that of Dinarius, but this time 4-4.
You are in 6NT at MP after an uncontested auction, bid in ♣. You are 4144 opposite 2524 (or 1534) and know you hold all the Aces and Kings, plus the Q♣. You receive a ♥ lead from what looks like 5 cards opposite 2, which you take realising that you have only the 3 remaining top tricks in the majors you will need all 4 tricks from each minor. To your surprise and relief, opponent's ♦ split 3-3.
Now you face the ♣ suit which is:

♣KQ87 in dummy
♣A963 in hand.

You start with the 3 to the K, with LHO playing the 2 and RHO the J.
RHO is a shifty character. You place him with 8 black cards against 5 held by LHO.
How do you proceed?

[kuhchung]

i can't really make sense of this but this is not RC. if RHO is grosvenoring you then so be it

[The_Badger]

Cashing the 4th ♦ seems better than tackling the ♣ suit.

[sfi]

There's a lot more going on in this hand than just the club suit, and you've already misplayed it. But let's start with the suit combination itself. The only relevant holdings are JTxx and J, and there are three JTxx holdings. Again, restricted choice tells us that the odds are 3:2 that RHO holds four of them if he will always try to Grosvenor us. And that is more likely with the number of cards in the black suit he is likely to hold. It's a pretty bad assumption that RHO would always play an honour from that holding though, for obvious reasons. More likely, RHO holds JT or JTx and you're just going to make the hand.

I'm not against playing for an opponent to be throwing away the setting trick just to mess with our mind, but I would like to be sure about it before trying. So let's look at the entire hand. Given that diamonds broke 3-3, dummy needs to be 1534 and the hand looks something like:

---

You need the DQ to get 4 tricks from the suit, so I added that as well. It's also important to know what they discarded when you cashed the fourth diamond, which should be done before touching the club suit because you might get useful information.

The misplay occurred at trick one. Ducking the heart would allow you to confirm the distribution in that suit and rectify the count for a squeeze - most likely either in hearts and diamonds or some sort of a double squeeze. If West failed to shift to a spade at this point, you would now be able to play for West holding Txxx in clubs and fall back on a double squeeze (West needs to guard spades and hearts, while East needs to guard spades and clubs). Your best play is still to try that by leading a low heart now, pitching a spade. It's less likely to work, since the opponents have more information, but it may still let you confirm your suspicions about the count.

If they do shift to a spade, then your realistic squeeze chances are gone. However, you can still get a count on the hand by cashing the second spade. If everyone follows, then you know West cannot be 1534. So either your count in hearts is wrong or RHO is playing games in clubs. Unfortunately, you no longer have enough transportation to cash the other top heart and find out for certain.

Given all this, the question is why would East deliberately throw away a trick? East can work out that no squeeze will function because the count is not rectified, so there is no technical reason I can see. Putting it all together:

• If West has one spade, I will play them for 1534 and cash the club ace.
  
• If West has more than one spade, unless I have strong evidence to the contrary I will assume I have misread hearts and West is 2434 and still cash the club ace.

In the end, I'll pay off to the possibility that East did Grosvenor me.

[pescetom]

sfi, on 2018-November-07, 13:59, said:

There's a lot more going on in this hand than just the club suit
.........

Thanks for a much better reply than the question as posed deserved - I added the detail I could remember, but really should have photographed the hand and memorised the discards to the 4th ♦ (East some small spade). Will do better next time. Yes your game plan makes a lot of sense. The play of the club A instead of the Q would have worked nicely, West turned out to be 1534.