[Lovera]

I have not found it talked around. Do you know how is ruled it or if in any bridge book are indicated suggests for how to do in this case ?

[The_Badger]

The first thing you need to do is recognise when is it favourable to sacrifice. And, even if seems obvious, knowing bridge scoring generally helps.

For example, if the opponents reach 7♥ non-vulnerable, and you can bid 7♠ as a sacrifice non-vulnerable too, how many tricks can you concede? Surprisingly you can still go down 6 tricks doubled at this equal vulnerability and turn a small IMP profit (1510 vs. -1400 = 3 IMPs)

And even if the opponents bid a vulnerable grand slam (2210) you can sacrifice profitably non-vulnerable doubled by going down 8 tricks (2000), and even 9 tricks (2300) is not a total disaster, except if it is a phantom sacrifice.

Knowing these figures off by heart is a good start.

Also, recognising that the Law of Total Tricks does not work at this level is also worth noting. Just because you may have a lot of trumps between the two hands doesn't necessarily mean you can take a set number of tricks.

As for the minutiae, the small expert details, where a certain bid or double at the 5th or 6th level indicates the number of possible defensive tricks a (possible) sacrifice bidder may hold, I can't pin any book down that carries these details, and I have an extensive bridge library. Maybe someone else who plays regularly at the top level can elaborate further.

[rmnka447]

The_Badger, on 2017-October-08, 12:18, said:

The first thing you need to do is recognise when is it favourable to sacrifice. And, even if seems obvious, knowing bridge scoring generally helps.

For example, if the opponents reach 7♥ non-vulnerable, and you can bid 7♠ as a sacrifice non-vulnerable too, how many tricks can you concede? Surprisingly you can still go down 6 tricks doubled at this equal vulnerability and turn a small IMP profit (1510 vs. -1400 = 3 IMPs)

And even if the opponents bid a vulnerable grand slam (2210) you can sacrifice profitably non-vulnerable doubled by going down 8 tricks (2000), and even 9 tricks (2300) is not a total disaster, except if it is a phantom sacrifice.

Knowing these figures off by heart is a good start.

Also, recognising that the Law of Total Tricks does not work at this level is also worth noting. Just because you may have a lot of trumps between the two hands doesn't necessarily mean you can take a set number of tricks.

As for the minutiae, the small expert details, where a certain bid or double at the 5th or 6th level indicates the number of possible defensive tricks a (possible) sacrifice bidder may hold, I can't pin any book down that carries these details, and I have an extensive bridge library. Maybe someone else who plays regularly at the top level can elaborate further.

Years and years ago, Harold Feldheim in a book on Swiss Team tactics outlined Positive Slam Doubles by the preempting side. After the slam bid, the next person on the preempting side Doubles if holding 2 or more probable tricks (versus a small slam) or passes with only 1 or no probable tricks. The next person on the preempting side to speak doubles with 1 probable trick or passes with 0 or 2 probable tricks. Now when the pass out seat double occurs showing 1 probable trick, doubler's partner can pass with the additional 1 probable trick hand or sacrifice with the no trick hand.

[Lovera]

The_Badger, on 2017-October-08, 12:18, said:

The first thing you need to do is recognise when is it favourable to sacrifice. And, even if seems obvious, knowing bridge scoring generally helps.

For example, if the opponents reach 7♥ non-vulnerable, and you can bid 7♠ as a sacrifice non-vulnerable too, how many tricks can you concede? Surprisingly you can still go down 6 tricks doubled at this equal vulnerability and turn a small IMP profit (1510 vs. -1400 = 3 IMPs)

And even if the opponents bid a vulnerable grand slam (2210) you can sacrifice profitably non-vulnerable doubled by going down 8 tricks (2000), and even 9 tricks (2300) is not a total disaster, except if it is a phantom sacrifice.

Knowing these figures off by heart is a good start.

Also, recognising that the Law of Total Tricks does not work at this level is also worth noting. Just because you may have a lot of trumps between the two hands doesn't necessarily mean you can take a set number of tricks.

As for the minutiae, the small expert details, where a certain bid or double at the 5th or 6th level indicates the number of possible defensive tricks a (possible) sacrifice bidder may hold, I can't pin any book down that carries these details, and I have an extensive bridge library. Maybe someone else who plays regularly at the top level can elaborate further.

Yes, but because i have the table with the "old" scoring, in the while how is changed? It seems to me : not vul vs nv 6 (instead of 7)= vul vs vul; not vul vs vul is now 8 (instead of 11) than vul vs not is 6 (instead of 5). Are they correct this ones for the grand slam sacrifice ?

[rmnka447]

Lovera, on 2017-October-08, 15:07, said:

Yes, but because i have the table with the "old" scoring, in the while how is changed? It seems to me : not vul vs nv 6 (instead of 7)= vul vs vul; not vul vs vul is now 8 (instead of 11) than vul vs not is 6 (instead of 5). Are they correct this ones for the grand slam sacrifice ?

The values of non-vulnerable sets were changed after down 3. It used to be down 1 was -100, down 2 was -300, down 3 was -500, down 4 was -700, ... increasing by -200 for each additional undertrick. It is now the same through down 3 -- down 1 is -100, down 2 is - 300, down 3 is -500. After down 3, it is now an additional -300 (similar to vulnerable undertricks) per undertrick. So down 4 is -800, down 5 is -1100, ...

[Lovera]

Let it more simple: when the "old" scoring was on (but if you want to use for your own using) i had (by me in accordling as tabled in "Il bridge naturale" by Mario Cucci pag. 304) estabilished so, it being an application of "Rule of 2 and 3" for the different cases: for partscore is the min of obscillation (2-3 not vul, 1-2 vul) i.e. 1 when vul; for game is applied the "Rule" that, i say, it's better to call ..of 1, 2 and 3 i. e. is 1 when vul vs not; for little slam add +2 at Rule tricks and at unpair vul -0(=inalterated) and +2 yet at resulting i.e. is 7(=2+3+2) when vul vs not;for grand slam add +5 and at unpair -1 and +3 yet so is 5(5+1-1) when vul vs not and 11(5+3+3) when not vul vs vul. In this way was easier to remember.
But as it is changed for an up-to-date the "new" scoring it'd be, only for slam situation, so: only at non vul vs vul add yet +1 i.e. is 6(=2+3+1) when not vul vs vul whilest for grand you add +4 (instead of 5) i.e. is 5(=4+1)when vul vs not and 8(=4+3+1) when not vul vs vul.Tell me if is right.

[Lovera]

rmnka447, on 2017-October-08, 14:09, said:

Years and years ago, Harold Feldheim in a book on Swiss Team tactics outlined Positive Slam Doubles by the preempting side. After the slam bid, the next person on the preempting side Doubles if holding 2 or more probable tricks (versus a small slam) or passes with only 1 or no probable tricks. The next person on the preempting side to speak doubles with 1 probable trick or passes with 0 or 2 probable tricks. Now when the pass out seat double occurs showing 1 probable trick, doubler's partner can pass with the additional 1 probable trick hand or sacrifice with the no trick hand.

It seems similar at "double negatif for slam(=contro negativo di slam) inserted in Roth-Stone system. Although the prevision of many tricks down (i.e. 4 or 6 when vul vs vul) allows to sacrifice in every vulnerabilty ?

[dokoko]

Lovera, on 2017-October-08, 15:07, said:

Yes, but because i have the table with the "old" scoring, in the while how is changed? It seems to me : not vul vs nv 6 (instead of 7)= vul vs vul; not vul vs vul is now 8 (instead of 11) than vul vs not is 6 (instead of 5). Are they correct this ones for the grand slam sacrifice ?

Do we really discuss in Expert-Class forum how a doubled undertrick is scored??????????? ROFL

[Lovera]

dokoko, on 2017-October-10, 13:40, said:

Do we really discuss in Expert-Class forum how a doubled undertrick is scored??????????? ROFL

Yes, no problem to change.

[Lovera]

---

(Meeting between the team of the United States and Great Britain in the World Championship at Bermuda on 1950). Note the double psychological maneuver of Stayman in S: on the 5 ♣ of the adversaries he says only 5 ♥ (while his goal is 6 ♥) and on the 6 ♣ let the partner to bid 6 ♥so that "the opponents, not distrusting of the distribution, let him play the slam". The events gave him reason. On Stayman's "forcing pass", Rapee declared 6 ♥, on which Louis Tarlo and Gardener passed. At the other table, S's bidding was more brutal and E-W did not let that the contract of 6 ♥ was played: S (Konstam) -W (Crawford) -N (Dodds) -E (Silodor)
1♣ (Silodor)
2♣ pass 3♥ 5♣
6♥ pass pass 7♣
X pass pass pass

[pescetom]

Why is Stayman's pass "forcing" if his raise to 5♥ was passable and passed ?

[Lovera]

pescetom, on 2018-June-26, 07:04, said:

Why is Stayman's pass "forcing" if his raise to 5♥ was passable and passed ?

Because not declaring immediately after 6 ♣ of E 6 ♥ you do not run the risk of being defended at 7 ♣ further ensuring the slam to Hearts by moving the statement on the partner and giving the idea that the contract may even fail (and thus increasing the chances of being able to play it).

[pescetom]

Lovera, on 2018-June-26, 10:56, said:

Because not declaring immediately after 6 ♣ of E 6 ♥ you do not run the risk of being defended at 7 ♣ further ensuring the slam to Hearts by moving the statement on the partner and giving the idea that the contract may even fail (and thus increasing the chances of being able to play it).

Yes I can see why South doesn't want to bid 6♥ for these reasons.
What escapes me is why his Pass should be forcing.
According to his bidding (at least as as East seems to understands it) his partner has no indication that there may be game in ♥.

[Lovera]

pescetom, on 2018-June-26, 12:34, said:

Yes I can see why South doesn't want to bid 6♥ for these reasons.
What escapes me is why his Pass should be forcing.
According to his bidding (at least as as East seems to understands it) his partner has no indication that there may be game in ♥.

Given the situation of vulnerability and the very positive response to the double the bidding will not end at 6 ♣ and Rapee will therefore have to declare 6 ♥ or X giving to Stayman the possibility to speak again.

[Lovera]

About IMPs (and around it) and score:
1) http://www.compensat...m/imp-table.php
2) the ACBL Duplicate Scoring: http://web2.acbl.org...stantScorer.pdf

This post has been edited by Lovera: 2018-June-28, 15:07

[johnu]

Lovera, on 2018-June-28, 11:00, said:

About IMPs (and around it) and score:
1) http://www.compensat...m/imp-table.php
2) the ACBL duplicate scoring:http://web2.acbl.org...stantScorer.pdf

Couldn't you find a deal newer than 68 years old? Bidding methods and philosophies change a lot in 68 years. In any case, the 1950 Bermuda bowl was scored at total points so linking to an IMP table has very limited application. Also, the scoring table for doubled non-vulnerable undertricks was changed in 1987 (this made non-vul sacrificing more attractive back then)

[pescetom]

johnu, on 2018-June-28, 14:15, said:

Couldn't you find a deal newer than 68 years old? Bidding methods and philosophies change a lot in 68 years.

Also because in the meantime screens were introduced

[Lovera]

It was made for a didacted aim. If anyone has a more recent hand (i said that this one seems to be few "spotted") can post it.

[dokoko]

Move this to "intermediate" pls.

Discussion is far from expert level.