[matmat]

(P) - 1♣-(1♦)-1NT all pass

lead, ♦K

Scoring: IMP

---

How would you play this?

Would the line be different at Matchpoints?


(ps. feel free to have the mods move this to BI if you think it belongs there).

[rhm]

Win and run the ♣8
I believe this play to be correct even at Matchpoints.

Rainer Herrmann

[pooltuna]

matmat, on May 18 2010, 01:16 AM, said:

(P) - 1♣-(1♦)-1NT all pass

lead, ♦K

Scoring: IMP

---

How would you play this?

Would the line be different at Matchpoints?


(ps. feel free to have the mods move this to BI if you think it belongs there).

Win the A♦ and ride the ♣8 seems like a 100% to make play

[H_KARLUK]

At 1st sight cl 8 then hook seemed well on IMPs, but on MPs say allowed by lefty could be sp 4 to 7.
However I prefer to play cl AK (10-8 at hand), in case 2nd round somebody pitched then will switch to sp7 does not matter IMPs or MPs.

5 cards cl outside, then 6% singleton, 27 % doubleton, 41 % trebleton. I forgot 4-1 and 5-0 probabilities of an honour card being. Either one should be maximum 25 %, maybe less than that.

When opps hold 5 card clubs probabilities are 3-2 68 %, 4-1 28 %, 5-0 4% .

Now hearts position:
7 cards outside, then 4-3 62%, 5-2 30.5 %, 6-1 7 %, 7-0 0.5 %
Singleton honour 1 %, doubleton 9%, trebleton 27 %.

Allright, those in turn enables people a general rule for finessing :

2 cards play for the drop
3 or 4 cards Finesse against the King but not against the queen or knave
5 or 6 cards Finesse against the King or queen but not against the knave
7 cards Finesse against the king, queen or knave.

ps. No worries, imo maybe a bit more card play&defense; even deceptive card play problems needed on BBF.

[gszeszycki]

AT MP no play is ever in a vacuum - cashing dia and playing clubs from top has roughly a 68% chance of scoring making 2 at MP for a tie for top. If we need a BIG score (probably near end of the session) thats the way to go.
AT IMPS the correct play is RHM advised running the club 8 to assure contract and still give us a chance to make 2. This is also the best play at MP under any conditions where average minus will serve us well (when club finesse loses).

[billw55]

deleted nonsense.

[rhm]

gszeszycki, on May 18 2010, 01:14 PM, said:

AT MP no play is ever in a vacuum -  cashing dia and playing clubs from top has roughly a 68% chance of scoring making 2 at MP for a tie for top. If we need a BIG score (probably near end of the session) thats the way to go. 
AT IMPS the correct play is RHM advised running the club 8 to assure contract and still give us a chance to make 2. This is also the best play at MP under any conditions where average minus will serve us well (when club finesse loses).

Finessing the ♣8 seems clear at IMPs.

So let us concentrate on Matchpoints:

It is crucial that East overcalled 1♦ and West led the king of ♦
It seems very likely that ♦ will break 2-6 or even 1-7. (East has overcalled on a nine high suit).
It follows that West has at least 11 unknown cards outside of ♦ and East at most 7 unknown cards.
This changes the odds whether the jack of ♣ will drop or should be finessed

That West has the jack of ♣ is not 50% but better than 61%
For the same reason the chance that West has 4 or 5 cards in ♣ is now more than 32% and in the unlikely event that East has 4 ♣ to the jack you should also finesse. The total probability for this is now almost 37%
A 3-2 break in ♣ is now according to my calculations less than 63%
So where is the advantage for playing for the drop?
Your chances for making 5 ♣ tricks by finessing is about as good as playing for the drop.
But if you play for the drop you either will make an overtrick or you will be down if the jack does not drop.
If you finesse you will either make an over trick or at least make your contract when the finesse fails.
Take into account that you are in a good contract and got a very favorable lead and there is a lot to be said to play safe for a positive score.
Run the ♣ 8.

Rainer Herrmann

[gnasher]

One factor arguing against RHM's line is that with a singleton club East might have bid again, especially with nobody vulnerable. With something like KQx AKx 987xxx x I'd probably have another go when 1NT came around to me. If you give East any less than that, West has an action over 1NT.

[rhm]

gnasher, on May 18 2010, 05:37 PM, said:

One factor arguing against RHM's line is that with a singleton club East might have bid again, especially with nobody vulnerable.  With something like KQx AKx 987xxx x I'd probably have another go when 1NT came around to me.  If you give East any less than that, West has an action over 1NT.

Sorry but I beg to differ.

There is a strong negative inference from West inaction:

The fact that West did neither overcall in a major over 1NT nor showed both majors with 2♣ makes it more likely, not less, that he holds length in ♣.
My calculated odds for the finesse are too conservative.

Rainer Herrmann

[gnasher]

rhm, on May 19 2010, 12:07 AM, said:

Sorry but I beg to differ.

There is a strong negative inference from West inaction:

The fact that West did neither overcall in a major over 1NT nor showed both majors with 2♣ makes it more likely, not less, that he holds length in ♣.
My calculated odds for the finesse are too conservative.

"Strong" is a strong word. Can you give an example of a hand where you think West would have bid because of length in the majors?

[rhm]

gnasher, on May 18 2010, 07:08 PM, said:

rhm, on May 19 2010, 12:07 AM, said:

Sorry but I beg to differ.

There is a strong negative inference from West inaction: 

The  fact that West did neither overcall in a major over 1NT nor showed both majors with 2♣ makes it more likely, not less, that he holds length in ♣.
My calculated odds for the finesse are too conservative.

"Strong" is a strong word. Can you give an example of a hand where you think West would have bid because of length in the majors?

This is easy.
My statement was, if anything, an understatement

We know that West has the king of ♦
If West has 6 ♠s, he would have to have ♠ AKQxxx, his pass and lead being clearly ridiculous.
If West had 6 ♥s, he would have to have in ♥ at least KTxxxx, which together with the king of ♦ would still justify a 2♥ bid over 1NT
If West held 5-5 in the majors he would have to have at least

♠KQxxx
♥Txxxx
♦K
♣xx

(with East having precisely the singleton ace of ♠ and the doubleton AK of ♥)
and West should still bid 2♣ over 1NT.

For all practical purposes West is marked with less than 6 cards in ♥ and less than 5 cards in ♠. Otherwise he would have enough distribution and/or HCP to act.

I have recalculated the odds for the drop and for the finesse under these conditions:

A 3-2 ♣ break reduces to 57.4%, in other words the chance that West has 4 or more cards in ♣ increases to 42.6%. (East having 4 or more ♣ is impossible)
The chances of the finesse and drop to gain 5 tricks in ♣ are practical identical.
This chance is according to my calculations around 64.3% .

Rainer Herrmann

[gnasher]

So, as I understand it, you have
- Identified one particular category of layout which is excluded by the auction
- Adjusted your calculations to exclude this category of layout
- Not adjusted your calculations for any of the other categories of layout which are also excluded by the acution.

Do you think there is any risk that this approach will reduce the precision of your estimates?

[rhm]

gnasher, on May 19 2010, 10:15 AM, said:

So, as I understand it, you have
- Identified one particular category of layout which is excluded by the auction
- Adjusted your calculations to exclude this category of layout
- Not adjusted your calculations for any of the other categories of layout which are also excluded by the acution.

Do you think there is any risk that this approach will reduce the precision of your estimates?

I do not on purpose exclude any relevant information from my calculation nor do I have any interest in favoring the finesse (plan 1) over the drop (plan 2).
I freely admit that the precision of probability calculations may be a bit misleading since they are dependent on the assumptions you are making.

Fact is that East overcalled a weak suit and then both West and East passed.
I see from the fact that West passed and from the lead I can deduce something relevant. This limits his strength and his major suit length
I do not see very much you can deduce from the final pass of East.
East-West have 20 points. Even if all the remaining HCP except for the known king of ♦ are with East, it is not clear whether bidding on (probably DBL) is clearly correct and Pass is not. If West has nothing bidding on from East's perspective may be a disaster. And even if East is 3=3=6=1 a DBL is not clearcut in my opinion.
It is not clear that East would overcall 1NT now with a 4 card major.
Maybe East would act with a void in clubs

Making the following assumptions:

WEST no 5 card ♠ suit, no 6 card ♥ suit at most a doubleton ♦
East no void in ♣, no 5card major

Then West will still have 4 cards in ♣ 38% of the time
Playing for the drop will now work 69.5% for 5 tricks while the finesse works "only"
64.5% of the time but will guarantee the contract.
This means the finesse will give you an overtrick 5% less often than playing for the drop, but 30% of the time you will be down playing for the drop.
After this favorable lead I have no doubts what will in the long term maximize your matchpoint score.

Rainer Herrmann

[Jlall]

Huh? If west bids 2C over our 1N that shows a limit raise in diamonds not the majors.

Anyways I tend to agree with rainer that we should hook even in MP.

[gnasher]

Suppose that West is 3424 and East is 3361. What do you think is the most that each opponent can have, consistent with the bidding?

jlall said:

Anyways I tend to agree with rainer that we should hook even in MP.

So did I, until I started thinking about what I was playing East for.

me said:

Do you think there is any risk that this approach will reduce the precision of your estimates?

I'd better nitpick this before somebody else does. RHM's precision is impeccable. I intended to question the accuracy of his figures.

[bd71]

Am I being dense here...is there any reason we shouldn't just start playing spades to learn more about the hand. At most, they can take 5 tricks off the top, but then we know a lot more about the hand on which to base our play in clubs and still try to make 8 tricks.

If/when we get to the point where we're down to one diamond stopper, we can broach clubs and use the best of the argurments presented in the thread up until now.

[gnasher]

bd71, on May 19 2010, 09:25 PM, said:

Am I being dense here...is there any reason we shouldn't just start playing spades to learn more about the hand. At most, they can take 5 tricks off the top, but then we know a lot more about the hand on which to base our play in clubs and still try to make 8 tricks.

They might cash three spades and exit with a club to endplay dummy.

[Jlall]

gnasher, on May 19 2010, 02:55 PM, said:

Suppose that West is 3424 and East is 3361. What do you think is the most that each opponent can have, consistent with the bidding?

jlall said:

Anyways I tend to agree with rainer that we should hook even in MP.

So did I, until I started thinking about what I was playing East for.

me said:

Do you think there is any risk that this approach will reduce the precision of your estimates?

I'd better nitpick this before somebody else does. RHM's precision is impeccable. I intended to question the accuracy of his figures.

I don't expect west to bid with a (34)24 9 count over 1N. He has club length and no fit. I know (from your comments) that you disagree.

I also don't expect a 3361 hand with 6 small diamonds to be that aggressive on this auction. I think from your comments you disagree.

[gwnn]

gnasher don't you play X of 1NT as the majors or do you play it as 'they stole my 1NT bid'?

[gnasher]

gwnn, on May 19 2010, 10:05 PM, said:

gnasher don't you play X of 1NT as the majors or do you play it as 'they stole my 1NT bid'?

I think I play it as somewhere between "takeout" and "values". Given Kx in partner's suit, I'd make it either on a balanced 10-count or a 4522 8-count.