[RunemPard]

Hello,

I am horrible at calculating odds for contacts. If anyone could tell me how good the odds on this grand slam are w/o a spade lead I would be most grateful.

Feel free to plan the play if you wish...we got the ♦7 led to us.

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[Phil]

If its the diagram you intended, then slam is really lousy. You need five club tricks which is 18%. You'll get a slightly more % if you cash the ♣K and the Q falls on your right (assuming South is playing), since you can count four club tricks and spade finesse or squeeze. even though the ♣Q from QT is common and should be found by a competent player. You'll get a little more for QT onside too. I don't know the exact number - 21% or so.

[han]

On a diamond lead, I'd win in dummy and play 3 rounds of clubs ruffing in hand. If clubs split 3-3 (35.5%) or the club queen falls doubleton (16.2%), I'll need diamonds 3-1 or 2-2 (90.4%), which gives 46.7%. If clubs split 4-2 (32.3%) with the queen not falling, I'll need diamonds 2-2 (40.7%) which gives 13.1%. If clubs split 5-1 I'm probably down (some chances if the queen is singleton).

So the total is roughly 59.8%, not a great grand but also not bad.

I think that Phil computed the odds for 7NT or something.

[Phil]

han, on 2012-August-23, 11:36, said:

I think that Phil computed the odds for 7NT or something.

Yes, thats what the original diagram had.

[RunemPard]

Phil, on 2012-August-23, 12:06, said:

Yes, thats what the original diagram had.

Yes, sorry...was working on figuring out how to change the bids.

[Cyberyeti]

Phil, on 2012-August-23, 12:06, said:

Yes, thats what the original diagram had.

With a comment that said don't reply yet, I'm working on this.

I think you play the 8♦ and win the J if necessary, then play a second trump, and cash 2 clubs, now unless good stuff has dropped you play for clubs 3-3.

This makes regardless of trump break when:

Clubs are 3-3 (35.5%)
Qx/Q10 clubs either side (1/3) of the 4-2s (16.2%)

It also makes when

W has stiff Q or 10 ♣ and 2 or less trumps, (1.2%)

So I get 52.9% but there may be better lines.

Edit: indeed, don't know how I missed the one han posted which I think is basically right with a very small deduction as you have to get back to hand after ruffing the fourth club with a ruff that needs to stand up.

[Fluffy]

han, on 2012-August-23, 11:36, said:

On a diamond lead, I'd win in dummy and play 3 rounds of clubs ruffing in hand. If clubs split 3-3 (35.5%) or the club queen falls doubleton (16.2%), I'll need diamonds 3-1 or 2-2 (90.4%), which gives 46.7%. If clubs split 4-2 (32.3%) with the queen not falling, I'll need diamonds 2-2 (40.7%) which gives 13.1%. If clubs split 5-1 I'm probably down (some chances if the queen is singleton).

So the total is roughly 59.8%, not a great grand but also not bad.

I think that Phil computed the odds for 7NT or something.

You also make when someone is 1-2 in the minors I think

[Phil]

"Preview Post" is a useful tool

[JLOGIC]

han, on 2012-August-23, 11:36, said:

On a diamond lead, I'd win in dummy and play 3 rounds of clubs ruffing in hand. If clubs split 3-3 (35.5%) or the club queen falls doubleton (16.2%), I'll need diamonds 3-1 or 2-2 (90.4%), which gives 46.7%. If clubs split 4-2 (32.3%) with the queen not falling, I'll need diamonds 2-2 (40.7%) which gives 13.1%. If clubs split 5-1 I'm probably down (some chances if the queen is singleton).

So the total is roughly 59.8%, not a great grand but also not bad.

I think that Phil computed the odds for 7NT or something.

This is the type of hand where you can easily see people missing slam though, so I would not like to be in it. It is not a claimer to bid slam, esp if you open 1C with 4432, or if your counterparts are weak, or if your teammates got in the bidding.

[FrancesHinden]

Cyberyeti, on 2012-August-23, 12:21, said:

With a comment that said don't reply yet, I'm working on this.

I think you play the 8♦ and win the J if necessary, then play a second trump, and cash 2 clubs, now unless good stuff has dropped you play for clubs 3-3.

This makes regardless of trump break when:

Clubs are 3-3 (35.5%)
Qx/Q10 clubs either side (1/3) of the 4-2s (16.2%)

It also makes when

W has stiff Q or 10 ♣ and 2 or less trumps, (1.2%)

So I get 52.9% but there may be better lines.

Edit: indeed, don't know how I missed the one han posted which I think is basically right with a very small deduction as you have to get back to hand after ruffing the fourth club with a ruff that needs to stand up.

It's easy to better this line by winning the DJ in hand and playing on clubs without playing a second trump first (unless West plays the Q or 10 on the first round)
You make on all the same layouts, plus you also make when East has a doubleton club and 1 or 2 trumps.

[FrancesHinden]

han, on 2012-August-23, 11:36, said:

On a diamond lead, I'd win in dummy and play 3 rounds of clubs ruffing in hand. If clubs split 3-3 (35.5%) or the club queen falls doubleton (16.2%), I'll need diamonds 3-1 or 2-2 (90.4%), which gives 46.7%. If clubs split 4-2 (32.3%) with the queen not falling, I'll need diamonds 2-2 (40.7%) which gives 13.1%. If clubs split 5-1 I'm probably down (some chances if the queen is singleton).

So the total is roughly 59.8%, not a great grand but also not bad.

I think that Phil computed the odds for 7NT or something.

You can add clubs 3-3 with the queen onside together with 4-0 trumps which is another 1.5% or so.

I can't decide if this line is better or worse than winning the first diamond in hand. They are the same any time clubs come in with one ruff and diamonds aren't 4-0.

Your line loses with trumps 4-0 and clubs 3-3 queen offside, or Qx of clubs offside.
Your line loses when RHO is 1-2 in the minors without the CQ

Your line gains when LHO is 2-2 in the minors without the CQ

The last of these looks more likely than the previous two put together, but I haven't added it up.

[MickyB]

FrancesHinden, on 2012-August-29, 08:34, said:

Your line loses when RHO is 1-2 in the minors without the CQ

I think it also loses when LHO is 1-2 minors without CQ

[FrancesHinden]

MickyB, on 2012-August-29, 10:19, said:

I think it also loses when LHO is 1-2 minors without CQ

They both go off then. I was only trying to compare two lines.