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Slam defence

#21 User is offline   Tramticket 

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Posted 2018-October-25, 01:51

View Postzhoraster, on 2018-October-24, 13:07, said:

You did make a huge mistake though, but in the bidding, when you failed to overcall with 2.

Good players are able to punish this sort of bid. This is a truly awful hand with a poor suit and no shape. You don't even have any desire for partner to lead it.

View Postzhoraster, on 2018-October-24, 13:07, said:

Your partner made a terrible lead (imo), which highly likely will present declarer a trick, given the bidding.

I think that "terrible" is over-stating this. One of the most difficult decisions for the player on lead is whether to go active or passive. This requires fine judgement and experts would not expect to get every lead right. Leading from a king is a very active lead and active leads are often the right choice against a small slam. The idea is that you are hoping that partner has a little something to help and is able to play the queen on this to promote your king as a winner, before declarer knocks out your (or your partner's) other winner. The danger in not playing an active lead is that declarer may knock out an ace in partner's hand, before your king has been set up as winner and declarer will have enough tricks from running a side suit to not need play the suit where you hold the king.

You should go active if you think that declarer has plenty of winners (from a side suit), but occasionally a more passive approach is needed. This will often be because declarer and dummy have is bid the slam based on high-card strength rather than shape. There is no side-suit to discard losers on. Any finesses will have to be taken, because the losers cannot be thrown on long suits or ruffed away.

Now re-read MikeH's comments on why he thinks that the auction suggests that the slam has been bid "on power". I think that on balance, Mike has got this right. But I certainly wouldn't say that an active lead was "terrible". On the actual hand, the only lead to defeat the slam is a heart - the other active choice.

View Postzhoraster, on 2018-October-24, 13:07, said:

You don't have to blame yourself for the defense.

Agreed. And a lot of Kudos for Thepossum, it is a common fault to get a bad result and immediately blame partner. It is far more constructive to have the attitude of "what could I have done to help partner" and a lot of credit goes to Thepossum for this. It is unfortunate that on this occasion it was partner who failed to read the cards correctly.
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#22 User is offline   zhoraster 

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Posted 2018-October-25, 22:47

View PostTramticket, on 2018-October-25, 01:51, said:

Good players are able to punish this sort of bid.

I've seen a lot of such "good players" on bbo. Their "goodness" is the desire to give opponents a lot of imps.

So please, good players, punish me! I would love to sacrifice at least two levels below your contract! This "punishment" will result in -1, sometimes -2, sometimes made, sometimes with overtricks, against a game.

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This is a truly awful hand with a poor suit and no shape.

And this is an awful hand - I agree - for the defense! Zero defensive strength with everything breaking even for the declarer.

For play, it is much better. Having six cards in hearts is already a shape. Opposite nothing, it is at least 3 tricks more than in a shapeless variant of this hand (xxx Qxxx xxx xxx).

Give me seventh heart, and I'll overcall 3 even without the queen (actually, without the queen I'm even more inclined to overcall as I know that my opponents are stronger). Add sixth ten in clubs to this - and I'll bid 5 (as bidding 4 won't stop them from finding 4) or 4nt (less likely, as it gives too much information to the opponents).

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You don't even have any desire for partner to lead it.

I don't. Equally I don't have any desire for partner to lead anything else. Do I desire that my partner leads towards my empty suits? No. I don't want my partner to be on the lead at all! And my preempt helps that too.

Moreover, preempts normally don't show any desire that my partner leads the suit called (sometimes he will even have a void there). What they do show is length in that suit and the desire to play rather than defend.

And yet moreover, further you'll contradict yourself saying partner could promote his king leading towards your queen. But we'll discuss this in time.

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I think that "terrible" is over-stating this.

No it's not.

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This requires fine judgement and experts would not expect to get every lead right. Leading from a king is a very active lead and active leads are often the right choice against a small slam.

I've seen a lot of such "experts" on bbo. Besides naming themselves experts, they frequently write "prefer fast play" in their profile, which hints at the real level of judgement involved.

Leading from a king is indeed often a right choice against a small slam but

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The idea is that you are hoping that partner has a little something to help on this to promote your king as a winner, before declarer knocks out your (or your partner's) other winner

even a beginner needs very little judgement to understand it isn't the right choice now. He just needs to hear the bidding and count his points to infer that after the opponents reached their slam in few bids, it is highly unlikely that his partner has anything at all, not even speaking of the queen. I would say there is 95-99% probability he has zero points.

And what would your active lead achieve? Just helping the opponents to get clubs right. Guessing the king, guessing the ten (this can be crucial too!) So in some 70-80% of the cases your active lead is a valuable gift for the declarer, which gives him his contract.

And moreover, even if your partner does have a queen, your lead will in most cases only help the declarer to win his slam. Say, your partner has Q75, and the declarer, A96 opposite J83; there are two club losers unless clubs are led. It is, of course, much safer to lead from a suit headed by a king when your partner has a long queen (which he might have shown with his 2 bid).
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#23 User is offline   zhoraster 

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Posted 2018-October-25, 23:31

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I did consider a 2H interferennce but haven't done it on such a weak hand before.


Of course, normally you shouldn't overcall with hands like that. But after your partner had failed to open (and only after that) this is absolutely necessary, as I have explained.
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#24 User is offline   Tramticket 

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Posted 2018-October-26, 02:33

View Postzhoraster, on 2018-October-25, 22:47, said:

I would love to sacrifice at least two levels below your contract! This "punishment" will result in -1, sometimes -2, sometimes made, sometimes with overtricks, against a game.


Or you might go for 1,400 or 1,700 against their game .....



You might get away with it sometimes - particularly against weak random opponents on BBO. But good players will be able to punish you when it is right to do so and will not be unduly inconvenienced in their constructive auction.

Over-calling on this hand is poor advice to post on a Novice and Beginner forum.
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#25 User is offline   zhoraster 

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Posted 2018-October-26, 07:04

View PostTramticket, on 2018-October-26, 02:33, said:

Or you might go for 1,400 or 1,700 against their game .....

Of course, one might. Not with the hand you pictured, but it is possible.

But the probability of EW getting a higher score by setting 2 than by playing their own contract is very low.

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You might get away with it sometimes - particularly against weak random opponents on BBO. But good players will be able to punish you when it is right to do so and will not be unduly inconvenienced in their constructive auction.

The "sometimes" you are referring to now is a fraction of already very small fraction of deals, like the one you pictured.

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Over-calling on this hand is poor advice to post on a Novice and Beginner forum.

There's no novice bridge or beginner bridge. Bridge uses the same logic on any level. And I have given mine arguments for overcalling, they are hopefully not very involved for a novice to understand them.

And there can't be a universal advice which works in 100% of cases. For each advice it is possible to construct a hand, maybe even many hands, where it fails. My advice works well for an overwhelming majority of hands, so I find it suitable.

And you didn't comment on everything else - does it mean you agree on that?
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#26 User is offline   Tramticket 

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Posted 2018-October-26, 08:20

View Postzhoraster, on 2018-October-26, 07:04, said:

There's no novice bridge or beginner bridge. Bridge uses the same logic on any level. And I have given mine arguments for overcalling, they are hopefully not very involved for a novice to understand them.


You certainly won't find any experts over-calling 2 on this hand, or advising such an over-call. You will not find this bid recommended in any text books. Yes, bridge uses the same logic on any level and this is a very bad bid on any level. Novices and beginners do not deserve to have to try to filter out this type of advice.

If you tried to apply Culbertson's rule of 2 and 3 to this pre-empt, you would expect to provide five tricks at this vulnerability. Even if the other hands around the table are evenly distributed, this holding only rates to score three tricks. It is the big holes in the suit that make this bid so bad. Strengthen the suit to QJT9XX and the bid would still be risky but would make more sense. The chances of playing in 2 doubled are far higher than you estimate, I have given one example hand where you will go for a telephone number, but there are many other ways that this bid could lose out. The bidding will not end with you playing 2 undoubled and knowledge of your heart length will often assist the opponents in the bidding or the play. Worse still, your partner might sacrifice at a high level expecting you to have some genuine suit quality in hearts.

Yet you claim that it was a "huge mistake" to not overcall 2.
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#27 User is offline   zhoraster 

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Posted 2018-October-26, 09:38

View PostTramticket, on 2018-October-26, 08:20, said:

You certainly won't find any experts over-calling 2 on this hand, or advising such an over-call


I gave my arguments and logic, but you rather appeal instead to Culbertson, rules, books, and experts. No point to discuss.

Speaking of experts, I've started a poll, let us see.

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Yet you claim that it was a "huge mistake" to not overcall 2.

I agree, the word "huge" is an exaggeration. But it is a mistake imo, and I explained why.
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#28 User is offline   mikeh 

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Posted 2018-October-26, 09:56

View Postzhoraster, on 2018-October-25, 23:31, said:

Of course, normally you shouldn't overcall with hands like that. But after your partner had failed to open (and only after that) this is absolutely necessary, as I have explained.

You have not 'explained' anything. You have made a claim and advanced a very bad argument in favour of it.

Others have pointed out that making overcalls, even those known to be weak, on very weak hands with very bad suits can lead to the opponents extracting a large penalty.

Your response, that you invite such a penalty, suggests that you do not understand the argument, perhaps because it contained an unstated assumption that you failed to pick up on.

The 'going for a number' problem is a valid problem. It presupposes, for much of its strength, that the opponents know what they are doing.

Good opponents will brush aside weak overcalls when their hands tell them that they should be aiming higher. In baseball there is a situation in which a batter hits an easy out...and the fielder has a choice of who to put out...the hitter or a base-runner...he takes, usually, the easier 'sure thing' play. We speak of fielder's choice in bridge as well: a bidder makes a call that presents the opps with two winning choices and good opps are usually able to choose the one that works best for them.

So bidding 2H will usually NOT go for a number, since most of the time West will not have an obvious penalty situation available. In that case, since 2H is not much of a preempt, he will usually simply bid on to the best contract. Every now and then, however, he has an easy penalty, and you go for 800 against a game, or worse.

It's not that 2H rates to go for a number...it usually won't....but it may go for a number and, more importantly, it carries all kinds of other costs to which you see oblivious.

I would not bother to go into detail about how bad your advice is but the OP has indicated that he sees wisdom in your advice and may bear it in mind in future games. In other words, your advice threatens to actively damage someone who is clearly eager to learn and whose basic understanding of the game does not yet permit him to readily identify terrible advice.

2H should be descriptive. Bridge is a partnership game and partners are not merely allowed but supposed to take part in the auction, and the play, based upon the description you provide during the auction. This description can be positive, in the sense that you take a bid, but it can also be negative...many beginning and indeed many intermediate players forget that negative inferences are extremely important....no expert ignores them.

If you bid 2H over 1D, your partner has to be able to play you for a reasonably defined range of hands. Sure, he passed, but all that means is that he doesn't have a hand with which he wants to open. It does NOT mean that he has a hand on which he will forever after pass, especially if you take a bid. Say he has some heart support....now he will raise, and now you are not getting doubled in 2H...you're getting doubled in 3H or 4H or even 5H (when he mistakenly thinks that he should be saving).

An intelligent partner will place you with something akin to KQ109xx in hearts and, if that's what you have, usually a side K or Q. He may over-compete. He may lead the Ace from AJx with the King being to your left. He may choose the K of hearts from Kx rather than a more effective lead.

Sure, sometimes the bad overcall gets a winning result...here the overcall would have led to a heart lead, which would have been effective had they still reached 6S. However, bridge is, in addition to being a partnership game, a game of percentages. One of the reasons that the game is so hard to learn is that bad plays and bad bids sometimes generate good outcomes and it is human, though incorrect, to reason that a good result must mean that we did something good in the play or the bidding. It doesn't.

On one level that makes me happy. I make enough mistakes that, if the game always punished bad decisions, I'd never win anything. More importantly, the game would be so brutal that very few would play it. On another level, it makes it difficult to teach the game. I can argue that playing to drop the stiff King when holding a 10 card fit missing only the King is wrong (as it is, when one has no other meaningful information) but when the printout on the hand record says that one can make 12 tricks by doing so, all kinds of bad players will argue until they are blue in the face that it is an ok play.....usually arguing that once LHO (dummy having the AQJxxxx) follows low, there are only 2 cards left...the K and a spot...and it's as likely RHO has the K as that he has the spot. The fallacy would be obvious to many, but a lot of bad bridge players will allow the fact that the King was stiff offside on this actual hand to influence their thinking.

So, yes, bidding 2H here would 'work' but that is not a good reason for arguing that the call is a smart all, let alone that it was 'essential'.

And if you do get away with this silly overcall, he will notice what you did. When next time you have a real 2H bid, he may be gunshy, and may do the wrong thing out of fear that you don't have your bid.

That latter point is something that poker players and solitaire players forget or ignore...so wrapped up in being the hero of every hand, and the maker of every partnership decision, that they are playing poker or solitaire and not playing bridge, even though they are sitting at the bridge table.

Arguing from authority is a poor approach to teaching, and asserting that 'I'm good, therefore listen to me' is distasteful, but having said that, I am pretty sure that those of us who disagree with you on this point have significantly better bridge credentials than do you.

Finally, once in a while, if one watches very good bridge, one will see a world-class player commit a very weak action. In my experience, this will happen at favourable only, and in the context of a method in which partner knows that one might do this. In the given situation, the vulnerability is wrong (even is not a good situation) and partner won't expect this.
'one of the great markers of the advance of human kindness is the howls you will hear from the Men of God' Johann Hari
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#29 User is offline   zhoraster 

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Posted 2018-October-28, 08:16

Ok, ok, some solid arguments at last.

I agree to most of them and admit that I was pretty carried away.

Anyway, I ran a double dummy simulation given the data (North passes, East opens 1). Here is the deal script:
proc notrump {hand min max} {
  if {![balanced $hand]} {return 0}

  set hc [hcp $hand]
  if {$hc < $min || $hc>$max} { return 0}

  return 1
}

south is "86 Q96542 84 975"

main {
  accept unless {[hcp north]>=12 || [hcp east]<11 || [hcp east]>21 || [spades east]>=5 || [hearts east]>=5 || [notrump east 15 17] || [notrump east 20 21] || [clubs east]>[diamonds east] || ([clubs east]==3 && [diamonds east] == 3)}
}


Now the statistics: out of 500 deals, 2 doubled compared to the best EW contract gives on average 324 poins, or 8 imps. (Also the median result is close: 254 deals yield 8 or more imps).

Of course, EW will be more inclined to punish when this is profitable for them, so here is more detailed statistics of losses :

In 136 deals (27.2% of all deals), 2 doubled gives a worse score than the best EW score. 77 of those (15.4% of all deals) lead to 1-4 imps loss (almost half of those is 1 imp), 39 (7.8% of all deals) lead to 5-9 imps loss, remaining 20 (4% of all deals), to the disaster of 10-14 imps loss.

Now in order to get a profitable result, the opponents should pass 2x and defend well. In around 8% of the deals, my result will be bad, in 4%, terrible (if they defend well).

Given the level of interference this bid creates, I'm taking the risks.

But now I agree with you, the bid is not essential, or even nice to recommend on this forum.
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#30 User is online   smerriman 

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Posted 2018-October-28, 14:12

Those stats don't make any sense. The opposition are guaranteed enough points for game. Virtually the only time that you will be playing 2x is when your LHO has at least 5 hearts and your RHO is short, reopening with a double.

I ran a sim of 500 hands that meet those conditions:

Down 3: 9/500
Down 4: 85/500
Down 5: 230/500
Down 6: 149/500
Down 7: 27/500

So you are guaranteed to score worse than the opposition's game; and almost certainly worse than the opposition's slam (if they even have one).

Even if I relax the condition to LHO only having >= 4 hearts, you're still far worse off to whatever the opposition would have bid to.

So if you find yourself in 2x, you will be losing a lot of IMPs.

Another case where you may lose IMPs is when you find yourself in 4x or 5x when partner sacrifices. This is never going to be a good result.

So in order to gain, your opposition must bid over 2 and not find the right spot. And this has to be a large gain to counter all of the IMPs losses from playing in hearts.

"Given the level of interference this causes", can you name a single hand where 2 prevents the opposition from finding their optimal contract? Let alone enough to make up for the above..
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#31 User is offline   nullve 

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Posted 2018-October-28, 17:20

View PostTramticket, on 2018-October-26, 08:20, said:

You certainly won't find any experts over-calling 2 on this hand, or advising such an over-call.

Welland-Auken?

View PostTramticket, on 2018-October-26, 08:20, said:

You will not find this bid recommended in any text books. .

Partnership Bidding at Bridge by Robson & Segal?
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#32 User is offline   Tramticket 

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Posted 2018-October-29, 09:58

View Postnullve, on 2018-October-28, 17:20, said:

Welland-Auken?


Maybe Welland / Auken have the systems to cope with this type of bid, I still wouldn't recommend it to novice / beginners.

View Postzhoraster, on 2018-October-26, 09:38, said:

Speaking of experts, I've started a poll, let us see.


Zhoraster's poll certainly suggests that a big majority on Bridge Winners, including some top-level, experience players are passing.
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#33 User is offline   thepossum 

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Posted 2018-October-29, 17:24

Dear all,

Thanks for all the analysis. I need to investigate it more. However what went through my head at that stage of the auction was going down 3, 4 or 5 doubled versus at that stage a likely game. That is quite borderline even at that vulnerability and you don't have the benefit of simulation and optimising imps. I reckoned on going down 500 or even 800+ points. I compared that to a game
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#34 User is offline   nullve 

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Posted 2018-October-29, 18:37

View Postmikeh, on 2018-October-26, 09:56, said:

An intelligent partner will place you with something akin to KQ109xx in hearts and, if that's what you have, usually a side K or Q.

Partner is a passed hand.
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#35 User is offline   thepossum 

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Posted 2018-October-29, 22:55

"partner is a passed hand",

Exactly
Partner could have very little even in a game.
RHO could have 12-19 points and I had that rubbish. I don't think I would ever jump to 2. If they were better hearts or any side stuff or better clues from RHO then maybe I would have considered it.i need to hear a good reason to change my mind ATM

I had max of 3 by myself possibly, maybe with a bit of luck 2-3 from partner. That goes down 2-4 tricks and there is risk of partner going higher

PS and I'm a naturally aggressive and competitive player 😀
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#36 User is offline   nullve 

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Posted 2018-November-01, 02:26



Robson & Segal recommend a WJO of 2 in this position (3rd seat NV vs. NV).

At least (Andrew) Robson is a world class player, btw.
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#37 User is online   smerriman 

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Posted 2018-November-01, 02:45

2 on that hand looks far better than 2 on the original though - it's more preemptive than hearts, you have an Ace, and the ability to ruff clubs.
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#38 User is offline   nullve 

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Posted 2018-November-01, 02:58

View Postsmerriman, on 2018-November-01, 02:45, said:

2 on that hand looks far better than 2 on the original though - it's more preemptive than hearts, you have an Ace, and the ability to ruff clubs.

They also recommend 2 (WJO) on

T754
KJT84
A73
4

in the exact same position.
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#39 User is offline   Tramticket 

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Posted 2018-November-01, 06:25

View Postnullve, on 2018-November-01, 02:26, said:


Robson & Segal recommend a WJO of 2 in this position (3rd seat NV vs. NV).


Apart from having three extra HCPs, the intermediates in the suit mean that, even on the worst possible splits, the suit is worth two tricks. I did comment on the 2 bid that it would be more reasonable on QJT9XX (note how you are guaranteed three tricks with this holding).

But this is still dangerous stuff to be advising a player new to the game. It requires a much more nuanced approach to hand valuations to understand the difference in playing strength between QXXXXX and QJT9XX and the danger in advising a new player to pre-empt on: JT984 743 A652 3 (both non-vul in third seat) is that the next time they hold J6543 743 Q652 K (non-vul Vs vul in 2nd seat) they will "recognise" the hand and make a weak jump over-call. Furthermore, their partner will also need to understand the philosophy of this type of ultra weak over-call, else the partnership will compete too high and run into difficulties. Yes, partner is a passed hand, but this can still contain values and partner will be keen to compete.
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#40 User is offline   zhoraster 

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Posted 2018-November-02, 08:12

View Postsmerriman, on 2018-October-28, 14:12, said:

"Given the level of interference this causes", can you name a single hand where 2 prevents the opposition from finding their optimal contract?

The hand posted.
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