commentator lead problem

[jdonn]

I will be diplomatic and call the post clamoring for an insane club lead "fuzzy math".

 

Care to try and put forth some constructive posts rather than making lame strawmen? I'm not 'clamoring' for a club lead. Anything could be right or wrong. I'm just trying to put forth an explanation why Han's double-dummy simulation suggests a club lead is best.

 

Oh wait - it's 'absolutely clear' as put forth by Ron that a heart is right, and a club is wrong.

 

What's wrong with a spade lead btw? if partner has K of spades, it could very well be the winning lead (partner will have the K of spades approximately 15-20% of the time?) If I thought that they're likely to be making unless we quickly set up some tricks, perhaps a spade is better than a heart.

1. You found some results (partner will have a heart honor x% of the time) and then jumped to some random conclusions (only lead a heart if they are making this contract y% of the time). You considered when a heart will blow a trick but not when a club will blow a trick or solve a guess, or when a heart is the most passive lead opposite no honors, or how you can have any idea what % of the time they are making, etc.

2. You claim partner will have at least one of A Q J of hearts 12+3=15% of the time, and now claim he will have the king of spades 15-20% of the time? I stand by 'fuzzy math'.

 

I don't think it's "absolutely clear" a heart is right. Just that a club is really terrible.

[kenrexford]

I think it is much better if partner just leads out of turn.

[effervesce]

I will be diplomatic and call the post clamoring for an insane club lead "fuzzy math".

 

Care to try and put forth some constructive posts rather than making lame strawmen? I'm not 'clamoring' for a club lead. Anything could be right or wrong. I'm just trying to put forth an explanation why Han's double-dummy simulation suggests a club lead is best.

 

Oh wait - it's 'absolutely clear' as put forth by Ron that a heart is right, and a club is wrong.

 

What's wrong with a spade lead btw? if partner has K of spades, it could very well be the winning lead (partner will have the K of spades approximately 15-20% of the time?) If I thought that they're likely to be making unless we quickly set up some tricks, perhaps a spade is better than a heart.

1. You found some results (partner will have a heart honor x% of the time) and then jumped to some random conclusions (only lead a heart if they are making this contract y% of the time). You considered when a heart will blow a trick but not when a club will blow a trick or solve a guess, or when a heart is the most passive lead opposite no honors, or how you can have any idea what % of the time they are making, etc.

2. You claim partner will have at least one of A Q J of hearts 12+3=15% of the time, and now claim he will have the king of spades 15-20% of the time? I stand by 'fuzzy math'.

 

I don't think it's "absolutely clear" a heart is right. Just that a club is really terrible.

Yes, partner won't have the K of spades 15-20% of the time. More like 5% of the time. I pulled that 15-20% number out of thin air to see if you'd even think about my post. Glad to see that you did.

 

I'm supposing that a club lead will blow a trick less often than a heart lead. A club lead will blow a trick if partner has Jxxx(x) or Qxx(x). A heart lead blows a trick if partner has nothing in hearts. Which one will occur more often?

[benlessard]

I think i can make a guess about why double dummy a club might be better. Double dummy the contract is almsot cold. So a passive lead might be better just for the overtricks. There are time when 3nt is not there because dummy has a useless club suit and few entries and a club is the only passive lead.

 

But since the goal is to put 3Nt down a club lead make little sense. Left to his own device and assuming partner got nothing declarer will make 4 or 5 clubs 2D + 2H + 1 or 2S. If we give the chance to declarer to establish trick everywhere he wont fail no matter what card partner got. If partner got nothing in H and nothing in S no matter what we lead declarer is heavy favorite to make 3nt. So i think we have to assume that partner got something in a major. A heart lead pretty much hope for 3H + 1S and a slow trcik (Q of D or J of S) but declarer will finesse us because we are short in clubs.

 

A spades lead work when partner has the K and we make 4s + 1H or might work when partner got the TS and a card elsewhere. (declarer KQx is spades or Hx on dummy)

[Finch]

I'm astonished at the idea that a club lead is passive.

[gnasher]

I'm astonished at the idea that a club lead is passive.

In the context of Han's simulation, where declarer is playing double dummy, a club lead is entirely passive.

[benlessard]

I'm astonished at the idea that a club lead is passive.

I hope its sarcasm.

[Finch]

I'm astonished at the idea that a club lead is passive.

I hope its sarcasm.

Are you being deliberately obtuse?

 

A singleton lead against 3NT on a blind auction is rarely passive. It will very frequently pick up something for declarer that he would (might) not find for himself - at least as often as any of the four-card suits we're thinking of leading.

 

Oh yes, and as soon as declarer works out you've led a singleton he will know what the rest of the your hand looks like, because you clearly were trying to avoid leading one of your 4-card suits. So you haven't just picked up the clubs, you've managed to reveal the entire layout.

 

As gnasher says, double dummy analysis is totally different, because the club lead won't cost if declarer has, say, Qx opposite AKJ9x or AJ10x opposite K9xx, or KJxx opposite A98x, or A9xx opposite Q108x or......

 

On this putative 4441 hand you simply don't have a passive lead.

[Guest Jlall]

On this type of lead problem, my partner had:

 

xxx KJxx 98x Kxx. The auction, starting on her left, was 2C p 2D p 2N p 3N. She led the D9. This was a good lead when the full deal was:

 

[hv=n=sxxht8xdjxxcqxxxx&w=sxxxhkjxxd98xckxx&e=sjt98h9xxxdaqxcxx&s=sakqxhaqdktxxcajt]399|300|[/hv]

 

Alas, I won the DA and shifted to the SJ... :lol:. Things like this are the reason leads like this work less often in real life than DD analysis would suggest.

[benlessard]

A club lead is unlikely to give away a trick, is very unlikely to develop a trick and its the least agressive lead i can make. As for giving up the layout of the hand this comment is also a joke. 95% of the time declarer best suit is going to be clubs. At trick 2 he will play club himself and notice the bad break probably at trcik 3. You have to be very naive (or play against very weak opponents) to hope that declarer will take finesses the wrong way.

[Cascade]

I personally hate leading 4 card suits against NT without a decent sequence. 3 or 5 card suits are fine, but not 4. (Unless I'm 5-4 in two suits, and during the bidding I've shown the 5 card suit - then I'd lead the 4 card suit).

 

Club for me.

Wtf is this post?

You have 4H, the opps have not looked for a Major suit fit, though a 433 is possible. Surely a H is the best lead. A club is off with the pixies when the opponents have bid this way.

Let's say partner has 5 points, the opponents 25. What's the chances of partner having a heart honor?

 

The outstanding honors are KQ spades, AQJ hearts, AKJ diamonds and AKQJ clubs (12 picture cards).

 

The relevant cards are A hearts, Q of hearts and J of hearts. The chances of partner holding AQ is nil, AJ is approximately 1/12C2, or 1/78. Let's be generous and make the chances of partner holding two honors in hearts as 3%.

 

What's the chances of partner holding 1 heart honor? Approximately 3C1*9C1/12C2, or 12%.

 

Thus the chances of partner holding anything in hearts is 15%. If partner has the jack, alot of the time the lead gives a free trick. Do you still think that a heart lead is 'obviously much better than a club', given it doesn't give a free trick about only about 10% of the time?

 

In essence, my argument is this: lead of a heart is probably best IFF (if and only if) their chances of making 3NT are >(80? 90?)%. Otherwise, a passive lead is best.

 

P.S. You'd better check your argument again (or at least put some clarifiers). Against 1NT-2NT, from AQxx KJxx Kx xxx what is your lead? By your argument you'd lead a heart or spade....

I think you are seriously underestimating the chances of heart honours.

 

On your assumption that partner has five points then these are the possibilities:

 

AJ

KQ

KJJ

QQJ

QJJJ

 

we can work out the odds of each of these combinations

 

There are three ways partner can have an ace and three ways to have a jack and 27C11 ways to have 11 small cards = 117341055

 

Similarly for KQ

 

There are three ways partner can have a king and three ways partner can have two jacks and 27C10 ways partner can have 10 small cards = 75926565

 

Similarly for QQJ

 

There are three ways partner can have a queen and one way partner can have three jacks and 27C9 ways partner can have 9 small cards = 14060475

 

Thus we can work out the relatively probabilities as:

 

AJ 0.292916401

KQ 0.292916401

KJJ 0.189534142

QQJ 0.189534142

QJJJ 0.035098915

 

Now partner has two honours in hearts

 

P(AJ)*1/3*1/3 + P(QQJ)*2/3*1/3 + P(QJJJ)*1/3*1 = 0.086364603

 

and partner has one honour in hearts

 

P(AJ)*1/3*2/3*2 +

 

P(KQ)*1/3 +

 

P(KJJ)*2/3 +

 

P(QQJ)*(2/3*2/3 + 1/3*1/3) + (queen and not jack plus not queen and jack)

 

P(QJJJ)

 

= 0.482875984

 

 

These numbers concurred with some empirical data that I generated.

 

I'm not sure what this means for your other conclusions.

[jdonn]

A club lead is unlikely to give away a trick

Do you have anything to back this up?? I totally disagree. It's not just solving a 2 way finesse. Give partner QJxx or something. Or like KT8x where you show declarer how to pick up the suit, or JTxx etc, there are tons of times it gives up a trick. Not to mention the times leading the right other suit would actually set up tricks!

[CSGibson]

Low heart. Give partner the A, Q, or 9 of hearts and I'm happy with the lead. Give partner the J of hearts and dummy the Q of hearts, and I'm happy with the lead. Not only will partner's lead back in the suit likely set up tricks, but declarer, being cognizant of that fact, will now take the diamond finesse into my "safe" hand if he has options

 

I have often led shortness when an auction "guarenteed" that partner had length and values in the suit. In this auction there is no such guarentee. Leading a club seems to be at best a guess, and at worst an attempt to pick off partner's holding in their long suit.

[benlessard]

Do you have anything to back this up?? I totally disagree. It's not just solving a 2 way finesse. Give partner QJxx or something. Or like KT8x where you show declarer how to pick up the suit, or JTxx etc, there are tons of times it gives up a trick. Not to mention the times leading the right other suit would actually set up tricks!

1- Because partner is poor he rate to have no pts in clubs.

 

2- If hes A or K and no spot it cost nothing. If he got Qxxx then declarer would probably have finesse him anyway (unless i falsecard my H or S lead). If hes got QJxx it cost nothing. (think about it and you will see) If K or Q with a spot it might not cost at all and sometimes declarer will play me for having 4 clubs.

 

Q9xx---AJ8x partner KTxx is safe anyway.

Q9xx----AK8x partner JTxx is safe.

 

By far the most likely case where its blow a trick is when Qxx but even with this declarer might still finesse him to keep him off lead.

 

Not only a club lead is unlikely to cost a trick but when you put thing in context by comparing a club lead VS the other lead its obvious to me that a club lead is very safe and very passive.

[gnasher]

If he got Qxxx then declarer would probably have finesse him anyway (unless i falsecard my H or S lead).

Are you saying that if I lead a card that shows a four-card heart suit, opener will play me for short clubs?

[Guest Jlall]

If he got Qxxx then declarer would probably have finesse him anyway (unless i falsecard my H or S lead).

Are you saying that if I lead a card that shows a four-card heart suit, opener will play me for short clubs?

lol

[benlessard]

Are you saying that if I lead a card that shows a four-card heart suit, opener will play me for short clubs?

Not necessarely play you for short club but he will finesse partner more often then is going to finesse you.

1- If your lead may suggest a 5+ card suit

2- If they got 7H.

3- Its more likely that he will want to keep RHO off lead then LHO.

4- if he can get a more complete count of the hand by playing 3 or 4 round of diamonds.

 

Some entry problem might induce declarer to finesse on your side. But the odds favor that for clubs he will finesse RHO.

[jdonn]

Do you have anything to back this up?? I totally disagree. It's not just solving a 2 way finesse. Give partner QJxx or something. Or like KT8x where you show declarer how to pick up the suit, or JTxx etc, there are tons of times it gives up a trick. Not to mention the times leading the right other suit would actually set up tricks!

1- Because partner is poor he rate to have no pts in clubs.

 

2- If hes A or K and no spot it cost nothing. If he got Qxxx then declarer would probably have finesse him anyway (unless i falsecard my H or S lead). If hes got QJxx it cost nothing. (think about it and you will see) If K or Q with a spot it might not cost at all and sometimes declarer will play me for having 4 clubs.

 

Q9xx---AJ8x partner KTxx is safe anyway.

Q9xx----AK8x partner JTxx is safe.

 

By far the most likely case where its blow a trick is when Qxx but even with this declarer might still finesse him to keep him off lead.

 

Not only a club lead is unlikely to cost a trick but when you put thing in context by comparing a club lead VS the other lead its obvious to me that a club lead is very safe and very passive.

Almost every statement in this post is untrue. I don't even want to waste my time arguing.

[skjaeran]

A club lead would never enter my mind. It might turn two tricks with partner in the suit into none, more often one to none. And help declarer with all four suits.

 

Which of my three suits is the best lead is not so clear though. I'm more inclined to lead a spade than most here - Axxx is a lead I abhor, AJxx is completely different. I think it's very close between the majors here.

[han]

I'm more inclined to lead a spade than most here - Axxx is a lead I abhor, AJxx is completely different. I think it's very close between the majors here.

I'm glad you say so. The double dummy simulation clearly makes the club lead look better than it is. But I see no reason why it should make the spade lead look better than a heart lead if in reality it is the other way around.

 

Why does almost everybody prefer hearts and if you do prefer hearts, why do you think the simulation incorrectly suggests spades is better?

 

(you in the last sentence was not meant as Harald but rather the rest)

[benlessard]

Almost every statement in this post is untrue. I don't even want to waste my time arguing.

Great argument. This really show why your bridge is better then mine. ;)

 

Anyway this is more mental masturbation then anything because im never leading clubs on that deal. Ill definitively want to make a sim to check if my S lead is better then a H lead.

  Why does almost everybody prefer hearts

Because they think i want to establish a trick and use the A of S as a side entry. Where i think this reasonnement is a bit off , is that if the K of H is badly placed (and partner doesnt do magic) we are unlikely to put this contract down anyway so might as well assume declarer got the A of H and see our K of H as an entry. So at the end you get Ajxx = more ambitious lead then (A)txx.

[Finch]

I'm glad you say so. The double dummy simulation clearly makes the club lead look better than it is. But I see no reason why it should make the spade lead look better than a heart lead if in reality it is the other way around.

 

Why does almost everybody prefer hearts and if you do prefer hearts, why do you think the simulation incorrectly suggests spades is better?

 

(you in the last sentence was not meant as Harald but rather the rest)

My reaction to the problem was to lead a heart for the traditional 'set the heart suit up and then I have the ace of spades as an entry' line. This is a prime example of the type of hand where the DD analysis of the club lead has much to do with real life, simply because in real life the club lead will pick up partner's club holding on many layouts where declarer would go wrong single dummy*.

 

I did a 100-hand single-dummy simulation and I now think it is less obvious than above, plus at least I think I understand why a spade comes out better.

 

I used the following constraints (roughly in line with what you might expect of me to have for a 1NT opening)

- Opener has no singleton and either 15-17 with no 5-card suit, or 14-16 with a 5- or 6-card minor

- responder has 9-12 HCP and either 4333 (any order) or no 4-card major plus no void and at most one singleton.

 

From this sample, I found that the contract was potentially beatable on 56 hands. On 7 of them it didn't matter what you led. A heart was necessary on 23, a spade on 19, either major worked on 3, a diamond on 3 and a club on precisely one.

 

('potentially beatable' means either definitely off, or declarer has a play problem which he might well get wrong)

 

I don't think the difference between the majors is statistically significant, but I do think a heart lead would be better if we didn't have the SJ and the DQ; one of the problems with the heart was that even when it is 'right' e.g. declarer has AJ9 and partner Qxx, we can't get partner in to play a heart through. When a spade is 'right' we don't need a second one played by partner (in fact when spades are our suit we usually need partner to play a heart through).

 

A major suit lead cost a trick about 60% of the time, with no difference between hearts and spades, and a diamond lead more than that (that 9 of diamonds is a valuable card if you don't lead away from the Q9) and anyway oppo have more diamonds between them.

 

If responder has 13+ HCP then a spade is by far the best lead as about the only way to beat the contract is to cash the first five spade tricks. That's why DD a spade wins over the space of all possible hands. If they had an invitational sequence I believe a spade lead will get relatively worse.

 

One prejudice I have that I confirmed is that a passive lead is definitely wrong. I found exactly one hand in a 100 (the one where the club lead was right) where the only way to have a hope of beating the contract was not to give a trick away on the lead. I hate passive leads against this auction even at matchpoints.

 

*it's a side issue, but based on 3 samples of 100 simulated hands a club lead costs a trick in the suit 25% of the time compared to declarer's normal line.

[han]

*it's a side issue, but based on 3 samples of 100 simulated hands a club lead costs a trick in the suit 25% of the time compared to declarer's normal line.

This is a wonderful comment. Could you elaborate?

[Finch]

*it's a side issue, but based on 3 samples of 100 simulated hands a club lead costs a trick in the suit 25% of the time compared to declarer's normal line.

This is a wonderful comment. Could you elaborate?

Without looking at whether it was a 'good lead' in terms of beating the contract (as I said, it was hopeless) I was interested in looking to see how passive a club lead actually is. By 'passive' I mean that leading one will make no difference in the number of tricks that declarer would make were he left to play on the suit himself. So on 75% of hands whether or not you lead a club doesn't affect the play in the suit, because either

i) Declarer is solid (AQxx opposite KJxx or whatever), or

ii) Declarer's normal line picks up partner's holding (Kxx in dummy AJ10xx in hand, or AQxx opposite K10xx etc)

 

On 25% of hands you cost a trick by leading the suit, because you pick up partner's holding, which is either

i) One declarer would never play for (Kx opposite AQJ9x)

ii) One where declarer would not usually play for that layout (e.g. AJ10xx in dummy opposite Kxx in hand, or Qxx opposite AK98x)

 

There are a few hands which are fuzzy e.g. A98x opposite Q1076 in hand, and I counted about half of these as costing (e.g. if declarer has to play on the suit himself and knows you have led a 4-card suit his choice of who to play for club length will depend on this combined holdings in all the suits).

 

The club lead actually turned out to be more passive than I had expected because of the combination of our diamond length and responder's lack of major suit length - if we were, say, 5521 or if responder had shown a 4-card major (e.g. 1NT - 2C - 2D - 3NT) I believe - although I haven't checked - that a club lead will cost more often.

 

I am vaguely interested to know why a club does so well DD, when on my simulation it virtually never beat the contract. Can you extract any of the hands where a club lead was successful and other leads weren't?

[gnasher]

Are you saying that if I lead a card that shows a four-card heart suit, opener will play me for short clubs?

lol

You may laugh, but a lot of otherwise sensible people do believe that such a play would be correct, possibly because Hugh Kelsey inexplicably said they should in Bridge Odds for Practical Players.

 

There is, in fact, some experimental evidence that they're right, but only if I happen to be in the opposing team.