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Sacrificing Opinions Please

#1 User is offline   sceptic 

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Posted 2006-June-27, 23:58

Hi

I make some really bad calls over contracts on occasions (to many to mention)

What sort of advice can you give about sacrificing, i.e.

how to evaluate what it will cost

how to work out how an unbid hand in a competitive auction will go down 2 tricks not the usual 3.4 or 5 I seem to arrive at

an odd question here

a 4 or 5 level opening bid is premptive, so is a preemptive overcall an intentional sacrifice or advanced sacrifice?(not quite sure I have explained myself well here)

anyway I just want some help as I seem to get either Tops or Bottoms for my sacrifice attempts, yet I never know whether or not I should have bothered
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#2 User is offline   paulg 

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Posted 2006-June-28, 02:01

sceptic, on Jun 28 2006, 06:58 AM, said:

Hi

I make some really bad calls over contracts on occasions (to many to mention)

What sort of advice can you give about sacrificing, i.e.

how to evaluate what it will cost

how to work out how an unbid hand in a competitive auction will go down 2 tricks not the usual 3.4 or 5 I seem to arrive at

an odd question here

a 4 or 5 level opening bid is premptive, so is a preemptive overcall an intentional sacrifice or advanced sacrifice?(not quite sure I have explained myself well here)

anyway I just want some help as I seem to get either Tops or Bottoms for my sacrifice attempts, yet I never know whether or not I should have bothered

Sacrificing is more of an art than a science but the principal aim remains to get the best score available on the board. I feel that this should be regarded as a long-term aim and so the occasional disaster is inevitable but should be seen in this wider context.

However, occasional should not become consistent ;)

The reason to pre-empt is that you believe this will give you a better score on the board. You aim to get this score by:
  • Going down less than the opposition's average score. For example, going down 2 doubled non-vulnerable for -300 against their non-vul (400+) or vul (600+) game.

  • Forcing the opposition too high when coping with your pre-empt

  • Removing the opposition's bidding space so they cannot fully explore the hand

From what I've seen, you do have a tendency to pre-empt 'twice' - that is, having made a pre-empt and forcing the opposition to guess their contract, you then save them by bidding again.

It is very rare, having made a pre-emptive bid, that the preemptor bids again. You have described your hand and so subsequent decisions should be made by your partner. Partner's raise may be pre-emptive, or it may be attempting to push the opposition into a poor contract.

In terms of judging whether it is worthwhile to sacrifice, that is largely down to experience (which you are clearly building). Distributional hands are better, so 7222 shape is worse than 7321 shape, 6421 better than 6322; honours in long suits rather than short.

Others will be more eloquent, but I think that 'bid once' is the best advice.

Quote

an odd question here

a 4 or 5 level opening bid is premptive, so is a preemptive overcall an intentional sacrifice or advanced sacrifice?(not quite sure I have explained myself well here)

There is little difference from a preemptive opening or overcall in terms of your goal. However, when overcalling the opposition have already started their dialogue so you know that they are more likely to be strong; on the other side the opener's partner knows more about the hand so is better positioned to evaluate whether to double or bid on.

This tends to mean that the suit quality should be better (or longer).

Paul
The Beer Card

I don't work for BBO and any advice is based on my BBO experience over the decades
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#3 User is offline   luke warm 

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Posted 2006-June-28, 04:31

i rarely sac, but when i do it's almost always based on LOTT
"Paul Krugman is a stupid person's idea of what a smart person sounds like." Newt Gingrich (paraphrased)
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#4 User is offline   mgoetze 

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Posted 2006-June-28, 05:15

There are some interesting points in Robson/Segals "Partnership Bidding in Bridge", available from http://www.geocities...neill_2000/sys/
"One of the painful things about our time is that those who feel certainty are stupid, and those with any imagination and understanding are filled with doubt and indecision"
    -- Bertrand Russell
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#5 User is offline   Wackojack 

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Posted 2006-June-29, 10:45

Pre-empts should be "one shot" bids. Don't even think of bidding again.
Avoid putting yourself in the "last guess" position.
Pre-empt to the maximum and then shut up
Use LOTT as a guide where possible.
Don't push your opponents into a game when you can't punish them.
Don't "walk the dog" even if has worked for you sometimes.
Learn to evaluate ODR (Offence/defence ratio)
Don't mastermind
Read Robson/Segal "partnership bidding"
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Soon: Mission illegal
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#6 User is offline   barmar 

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Posted 2006-June-29, 15:11

Look at the vulnerability, and apply the rule of 2-3-4. Assuming the opponents can make a game, you can afford to go down 1 at unfavorable vulnerability, 2 at equal vulnerability, and 3 when favorable. Then assume that partner can provide one offensive trick. Then count your expected offensive tricks, and add 2, 3, or 4 to get the level you should bid to unfavorable, equal, or favorable, respectively.

#7 User is offline   neilkaz 

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Posted 2006-June-29, 19:45

Wackojack, on Jun 29 2006, 11:45 AM, said:

Pre-empts should be "one shot" bids. Don't even think of bidding again.
Avoid putting yourself in the "last guess" position.
Pre-empt to the maximum and then shut up
Use LOTT as a guide where possible.
Don't push your opponents into a game when you can't punish them.
Don't "walk the dog" even if has worked for you sometimes.
Learn to evaluate ODR (Offence/defence ratio)
Don't mastermind
Read Robson/Segal "partnership bidding"

I completely agree with Wackojack.
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#8 User is offline   helene_t 

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Posted 2006-June-30, 03:20

Quote

I completely agree with Wackojack.
Me too.
The world would be such a happy place, if only everyone played Acol :) --- TramTicket
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#9 User is offline   hotShot 

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Posted 2006-June-30, 03:36

Don't waste your energy on sacrifices, they will come automaticly once you can evaluate your sides best contract.
If you want to sacrifice in a minor over 4M you need to be sure you can make 3m. If you want to sacrifice against a slam, 2(something) should make.
You should have an agreement about your preempts, and how many tricks are needed from partner to make. A rock solid stoneage agreement would be 2(3) tricks. Sort of a modern agreement would be LOTT, but it is not so accurate at the 5 level.
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#10 User is offline   P_Marlowe 

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Posted 2006-June-30, 05:51

Hi,

I just want to add two remarks:

Get partner involved in the decision process
and make partnership agrrements, stick with
them and build up partnership trust.

Wackojacks comments go in this direction,
e.g. Robson/Segals book is about partnership
agreements, and the same is true about the
sacrifices according to LOTT.

Just to give you an example:

Consider the situation

4H - (X)- Pass - (4S)
???

Usually one does not make a preempt beyond the game
level, i.e. it is possble that the 4H bidder holds a hand,
which may make 5H a cheap sacrifice.
One possible option would be to Dbl, sending this message
to partner: "Hey partner, I am willing to go on to the 5 level,
but if you think we can beat 4S, than we will give it a try."

And finally another point: If you think, you have a reasonable
chance to beat the contract, dont sacrifice.

With kind regards
Marlowe
With kind regards
Uwe Gebhardt (P_Marlowe)
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#11 User is offline   helene_t 

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Posted 2006-June-30, 06:22

Larry Cohen writes in "To bid or not to bid" that many otherwise good players, even life masters, sacrifice too often at the 5-level. I see the same often (allthough I rarely play against life masters). In general, players who haven't read Larry Cohen's book tend to compeed too much, not only at the 5-level.

At IMPs, a sacrifice is only worthwhile if it rates to be really cheap - such as -300 instead of -620, or -500 instead of -1430. If opps, too, think that it rates to be a cheap sacrifice, they are likely to bid one level higher. -500 instead of -620 is not worthwhile at IMPs, considering the risk of a phantom sacrifice.

At matchpoints, this is not true, but here there is another reason not to sacrifice too much: Opps may have bid a game or slam that wasn't bid by the field, so even if the contract is makeable and your sacrifice is cheap, you still rate to get a bad score. If your judgement is that this is likely to be the case, your only chance of getting a good score is to pass and try to beat the contract.
The world would be such a happy place, if only everyone played Acol :) --- TramTicket
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