[eagles123]

this was a disaster for us, what should have been a top ended up a bottom! the opponents were in 3NT by East - Matchpoints.

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I led a low diamond won by P's ace, then king dropping East's Q doubleton. on the third round of diamonds I chose to put the T under my p's Jack thinking club switch was relatively obvious for -2 rather than me winning the last diamond and it only being a probably -1. on the 3rd and 4th diamond east chucked 2 hearts and on the 4th diamond dummy chucked a club. Unfortunatley my P chose to switch to a Heart instead of a Club and the opps just cashed 9 tricks in Hearts and Spades = bottom when everyone else was in a Heart part score making +++

I don't know if I'm being too unfair on my P or not, maybe it's my fault for not being ruthless just taking the last diamond and at least ensuring the contract is down 1? Just thought the club switch would be kinda clear given dummy?

Thanks,

Eagles

[Cyberyeti]

Would need to hear the auction first.

[eagles123]

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this was the auction, East was showing 19-20 balanced in their system and neither pair showed an actual suit.

[Cyberyeti]

eagles123, on 2013-August-02, 04:23, said:

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this was the auction, East was showing 19-20 balanced in their system and neither pair showed an actual suit.

That's tough.

I'd have already got this wrong and led a club (if partner has xx(x) and an entry and declarer has the K, this may be necessary).

You have no idea if you're in a normal contract or not (19v4 no, 20v4 yes) although 19 is more probable than 20 by a fair bit so assume not.

You also might have led a club initially, unless partner has the K, you may well already be ahead so take the -1.

From partner's point of view, AKx, Axx, Qx, KQJxx or similar may also be possible for declarer where anything but a heart is only -1.

[eagles123]

this was the whole deal:

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[billw55]

I would think your play to trick 2 would be suit preference. Although that may require more partnership experience and trust than was available.

Absent that, Cyber may have a point about taking the certainty, especially if you think you are already ahead of the field based on the lead. On the other hand, you can place declarer with ♠AKx(x) which means the field may well be in 3♠ or 4♠, and certainly not getting a club lead from south. Also, some might find a way for west to declare, in which case cashing two diamonds followed by a club switch is glaringly obvious. Either way, it is quite easy to hold a spade contract to 8 tricks for either +50 or +100. So at matchpoints, the extra undertrick could matter a lot.

[phoenix214]

If we now look at the N hand, he knows you 6-7 points. If opener doesnt have 9 quick tricks then a passive lead is the best. From the biding you can tell that he doesnt have a good suit to set up tricks. Spades can be set up if he has AKx(x)(If partner has something in spades, declerar will have problems for 9 tricks). That means partner has a something in hearts, clubs or both. If he has something in hearts(more then Q), then leading the suit might cost a trick, so it`s not a good idea. On the other hand leading a club is safe, and doesn`t cost anything.

On the other hand you yourself can do something similar(After pard has shown AKJ of diamonds, you know he doesn`t have much else left). Again spades look like the best source of tricks. But if that is the case, then opps are playing the wrong contract. 4♠ shouold be the normal one and not 3NT. 4♠ has 9 tricks, and if you misdefened then it makes, so if you cash the A♣, then at worse you should get 50%, but normally more.

As regarding the lead. I like the !♦ lead, cause it does not give up a trick. A club lead might give it up because most of the times declarer will have the K♣. If you lead a diamond you don't make a finesse he cannot do for himself. Although i might have made a ♥ lead because they did not use stayman, but obviously that would be bad.

[mikeh]

I think this OP raises issues that are pretty esoteric for the N/B forum.

Firstly, the unblock of the diamonds: not many N/B players would think of that, so the OP is to be commended for being alive to the potential gain.

However, I think it was a case of not quite thinking far enough ahead: in particular, not putting himself in his partner's seat.

The unblock sends a very clear message: I need a switch. However, unless one has a choice of cards with which to send the message, it doesn't and can never convey information as to WHICH switch.

It's clear that the spade switch cannot be needed. Declarer won't hold a stiff spade, so if we have the K, we're going to get it.

However, we might easily hold the heart K and an Ace, and need the heart switch. Indeed, declarer's play is entirely consistent with that. It is also consistent with what he held, but my point is merely that partner has no reason to guess correctly.

Accordingly, when S unblocks, he knows he is getting a switch but he has no idea whether that will/should be a club or a heart. Assume it's 50-50.

How many mps will we gain by beating this contract 2 as compared to beating it 1?

It seems to me that we are already ahead of the field. We are definitely ahead of many (including all clones of me) because we didn't lead the (obvious to me) club. We may be ahead of the field in that the opps are simply too high.

All of this tells us that we shouldn't unblock: we should take our good board. I'd estimate beating this 1 trick as worth about 80% of the mps. The exact figure is irrelevant. So long as we expect more than 50% from going +1, the arithmetic makes unblocking an error.

By unblocking, we are tossing a coin. 50% of the time we'll gain 20% of the mps and 50% of the time we'll lose 80% of the mps.

By not unblocking, we win 80% all the time.

I wrote in another recent thread that mps isn't always about taking the maximum number of tricks. Sometimes the line that maximizes the number of matchpoints gives up on a play that MIGHT generate more tricks, in order to maximize the chances of getting a good score on the board.

[cargobeep]

mikeh, on 2013-August-02, 08:44, said:

It's clear that the spade switch cannot be needed. Declarer won't hold a stiff spade, so if we have the K, we're going to get it.

However, we might easily hold the heart K and an Ace, and need the heart switch. Indeed, declarer's play is entirely consistent with that. It is also consistent with what he held, but my point is merely that partner has no reason to guess correctly.

S's play is not consistent with that however. If S had AK♥, what would be the point of the unblock with diamonds 4-4?

So declarer has A♥.

[cargobeep]

With AK♠ A♥ Q♦

That leaves East with maximum of 7 more points (small psych) or a minimum of 5 more points (small psych).

The possiblities are

1. KQ♣ - Club shift guarantees contract goes down one, Heart shift is down two
2. AK♣ - Hearts is best - declarer may duck the A♥
3. AQ♣ - irrelevant play
4. K♥A♣ - doesn't matter
5. K♥K♣ - club shift wins
6. A♣K♣ - club shift wins

So if we remove the plays that are inconsistent with the play or irrelevant, we get

KQ♣
AK♣
K♥K♣

Either one could in theory be correct...unfortunately partner doesn't have J of spades, so any of the options could fit the opening range.

[billw55]

mikeh, on 2013-August-02, 08:44, said:

(lots of other stuff and)

By unblocking, we are tossing a coin. 50% of the time we'll gain 20% of the mps and 50% of the time we'll lose 80% of the mps.

By not unblocking, we win 80% all the time.

I wrote in another recent thread that mps isn't always about taking the maximum number of tricks. Sometimes the line that maximizes the number of matchpoints gives up on a play that MIGHT generate more tricks, in order to maximize the chances of getting a good score on the board.

Mike, your analysis is good, but it seems to assume that NT is the normal contract. But a spade contract seems more likely, and also easier to set from either direction. So I don't think it is so obvious that we are "ahead of the field".

Also at trick 2 when north cashes the ♦A, and east drops the queen - cannot south now give a suit preference signal? Then after unblocking on trick 3, north knows which suit to switch to?

[mikeh]

cargobeep, on 2013-August-02, 09:14, said:

S's play is not consistent with that however. If S had AK♥, what would be the point of the unblock with diamonds 4-4?

So declarer has A♥.

Where did I say that S holds the heart AK? I said the heart K and 'an Ace', and I would have thought that all would have understood I was referring to a black Ace. Apparently not.

[mikeh]

billw55, on 2013-August-02, 09:47, said:

Mike, your analysis is good, but it seems to assume that NT is the normal contract. But a spade contract seems more likely, and also easier to set from either direction. So I don't think it is so obvious that we are "ahead of the field".

Also at trick 2 when north cashes the ♦A, and east drops the queen - cannot south now give a suit preference signal? Then after unblocking on trick 3, north knows which suit to switch to?

As to your first point, when I originally worked on my post, I had stuff in there about spade contracts. However, it gets complex. We don't know the level at which they would play. E has a ruffing value, tho repeated trump leads could eliminate that at the risk of allowing declarer to run the heart suit. They will often but not always make an extra trick in spades to compensate for being a level higher, and they might not even be a level higher! While the spade issue does complicate matters, I didn't and don't feel that we can assess whether we are ahead or behind the spade players, and so I would ignore it at the table. If, otoh, I were to conclude that those playing in spades were going 2 down more often than they were making their contract, then that would influence my assessment of the odds. As it is, given dummy and the meaning of the auction, I didn't and don't feel able to come to that assessment.

Your second point is very well taken, but as I said in my first post, I complimented a N/B player for visualizing an unblock at trick 3. I think that anyone who, as N, looked at the 3rd round unblock and reasoned: if partner wanted a heart, he could have unblocked at trick 2 and then played his highest (of 2) remaining spots...he didn't....he unblocked only at trick 3...therefore it's a club....would have shown that he is probably expert level. I agree with you that this IS a valid way of thinking, but I was addressing the OP in which the OP was wondering whether he should or shouldn't have unblocked when he did...ie should he have tried to win the last diamond.

In doing so, I overlooked the implications of trick 2, so good catch.

[billw55]

mikeh, on 2013-August-02, 10:20, said:

As to your first point, when I originally worked on my post, I had stuff in there about spade contracts. However, it gets complex. We don't know the level at which they would play. E has a ruffing value, tho repeated trump leads could eliminate that at the risk of allowing declarer to run the heart suit. They will often but not always make an extra trick in spades to compensate for being a level higher, and they might not even be a level higher! While the spade issue does complicate matters, I didn't and don't feel that we can assess whether we are ahead or behind the spade players, and so I would ignore it at the table. If, otoh, I were to conclude that those playing in spades were going 2 down more often than they were making their contract, then that would influence my assessment of the odds. As it is, given dummy and the meaning of the auction, I didn't and don't feel able to come to that assessment.

Your second point is very well taken, but as I said in my first post, I complimented a N/B player for visualizing an unblock at trick 3. I think that anyone who, as N, looked at the 3rd round unblock and reasoned: if partner wanted a heart, he could have unblocked at trick 2 and then played his highest (of 2) remaining spots...he didn't....he unblocked only at trick 3...therefore it's a club....would have shown that he is probably expert level. I agree with you that this IS a valid way of thinking, but I was addressing the OP in which the OP was wondering whether he should or shouldn't have unblocked when he did...ie should he have tried to win the last diamond.

In doing so, I overlooked the implications of trick 2, so good catch.

I agree that at B-N level, just setting the contract is by far the best move. In this case, OP both unblocked and asked a thoughtful question, to me that says he is ready to start thinking about the situation at an I-A level. That is why I went ahead with it.

[eagles123]

thanks everyone, some very interesting points. Firstly, sorry if I put this in the wrong section of the forum, I am aware that it's not really a novice beginner issue but then again there's not a lot intermediate about the intermediate/advanced forum, especially in terms of the advice given, which is why I prefer posting here. Certainly at some point i'll start posting in I/A as the last thing I want to do is put off genuine beginners seeking advice on more basic issue.

I see now that the switch isn't quite as clear as I thought incase I did have CA and HK. At the time I thought with both major suit queens in dummy the only reason I would have for wanting P on lead would be that I had something over declarer and the only real possibility was in clubs. I also see that I should have realised we would already be ahead of the field on the lead/a lot of the field would be playing in a part score and taken the safe approach. I would love to say I unblocked on the 3rd diamond to show suit preference to clubs but I can safely say that's not the case!!

[mike777]

dup

[mike777]

eagles123, on 2013-August-02, 12:21, said:

thanks everyone, some very interesting points. Firstly, sorry if I put this in the wrong section of the forum, I am aware that it's not really a novice beginner issue but then again there's not a lot intermediate about the intermediate/advanced forum, especially in terms of the advice given, which is why I prefer posting here. Certainly at some point i'll start posting in I/A as the last thing I want to do is put off genuine beginners seeking advice on more basic issue.

I see now that the switch isn't quite as clear as I thought incase I did have CA and HK. At the time I thought with both major suit queens in dummy the only reason I would have for wanting P on lead would be that I had something over declarer and the only real possibility was in clubs. I also see that I should have realised we would already be ahead of the field on the lead/a lot of the field would be playing in a part score and taken the safe approach. I would love to say I unblocked on the 3rd diamond to show suit preference to clubs but I can safely say that's not the case!!

If no one has mentioned it...Switch in time ...Obvious Shift is the name of a very famous book that details when to switch or not and what suit is the "OS"

IMO this is a great book and strongly recommend you read it.

http://www.bridgewit...viousShift.html

http://www.ny-bridge.com/bt/time.html

[Antrax]

It's a great book but is it really for N/B?

[PhilKing]

Unblocking at trick two was never on the agenda. Apart from it sending the wrong message, at this stage declarer could still have held QJ9 of diamonds.

As pointed out by Bill, South had a choice of spots before the unblock, so by playing lowest then unblocking, he wants clubs. Playing the lowest card is not in itself suit preference - only when coupled with the third-round unblock. As a practical matter, it is probably best to settle for one off, but if you are part of an aspiring partnership, striving for perfection is fine unless the cost of being wrong is too high. Then it is best to just discuss how you would defend for two off if the same position comes up after you have discussed the theory behind it.

[Fluffy]

East discarded 2 hearts on the diamonds, he cannot have 9 tricks after and partner's heart back is ok, so something is wrong.