Bidding theory-2 Overcalls, takeout x etc.

[mike777]

Comments and your thoughts welcomed on this thread.

 

I hope to get some feedback on the whole philosophy of overcalling, wjo, takeout doubles, etc.

 

It is commonly accepted wisdom that bidding first conveys a huge advantage.

I will leave that issue for another thread but feel free to touch on it if you wish.

 

In this post, the opponents have opened at the one level and either we are in the direct overcall seat or responder has bid something and we are now in 4th seat.

 

Many issues to consider here:

1) constructive overcalling vs destructive.

2) lead directing overcalls

3) telling the opp where the cards are if we bid

4) Assuming the decision is somewhat close is overcalling very often superior to a takeout x especially when the auction may get competitive or we may have to make a 4 level decision? Even if we have a 2 suited hand 4-5 hand?

5) Difference in Imp vs MP play?

6) Vul

7) passed hand bidding

8) Other issues.

[Gerben42]

1) constructive overcalling vs destructive.

2) lead directing overcalls

3) telling the opp where the cards are if we bid

4) Assuming the decision is somewhat close is overcalling very often superior to a takeout x especially when the auction may get competitive or we may have to make a 4 level decision? Even if we have a 2 suited hand 4-5 hand?

5) Difference in Imp vs MP play?

6) Vul

7) passed hand bidding

8) Other issues.

 

1. Simple overcalls for me are CONSTRUCTIVE. This means you either have a good suit or good values. On the 2-level, preferably both.

 

2. On the 1-level this can happen. Also by a passed hand. See #1 though...

 

3. Don't worry too much about that, you are trying to find a contract of your own.

 

4. I would consider overcalling more as an alternative to Dbl then suit. Lawrence style is that this shows a GOOD hand, not just a good hand.

 

5. MP you can get away with some bad overcalls, but I keep it to a min.

 

6. Vul vs not I prefer intermediate jump overcalls.

 

7. Depends a bit what opening bids you play. Playing Fantunes you probably only have 4-card overcalls and weak 2 bids left.

[hrothgar]

The way that you are structuring this discussion seems to pre-suppose that opening bidding and defensive structures can be considered in isolation from one another. In actuality, there is an enormous amount of feedback between these different bidding modules. You can't hope to reach any reasonable conclusion about the merits of an opening structure unless you also consider how players will adapt their defensive methods and vice-versa...

 

Back in the day, when I was working on my Economics degree, most of my work was in a sub-branch called "Game Theory". Most of Economics boils down to some kind of constrained optimization problem. For example, I provide the cost for different inputs and a market demand curve, you tell me what quantity of the product one should produce in order to maximize profits. Game theory focuses on examples where there are multiple strategic actors. My profits depend not only on the quantity that I produce, but also on the quantity that you produce. The Holy Grail of Game Theory is find a "equilibrium". An equilibrium is a stable point in the system. Neither player will have an incentive to change their strategy. If the equilibrium is stable, the system will converge on this point.

 

If we return to bridge, I think that a number of different bidding eco-systems have evolved over time. Case in point: Traditionally, there have been some very significant differences in the definition of a direct seat double between Europe and the United States. In the US, a double of a 1♥ opening is "takeout". In much of Europe (Italy especially) the double was much more nebulous and included a much wider variety of hand types. There are a number of possible explanations for this difference. However, I suspect that differences in definition of the 1♥ opening had a significant impact.

 

Here once again, I suspect that the topic area being discussed is far too broad to reach anything approaching consensus. We can't even agree about what constitutes a reasonable defensive to a 15-17 HCP NT opening. I doubt that this thread is going to produce anything more conclusive than "this is complicated"

[mike777]

The way that you are structuring this discussion seems to pre-suppose that opening bidding and defensive structures can be considered in isolation from one another. In actuality, there is an enormous amount of feedback between these different bidding modules. You can't hope to reach any reasonable conclusion about the merits of an opening structure unless you also consider how players will adapt their defensive methods and vice-versa...

 

Back in the day, when I was working on my Economics degree, most of my work was in a sub-branch called "Game Theory". Most of Economics boils down to some kind of constrained optimization problem. For example, I provide the cost for different inputs and a market demand curve, you tell me what quantity of the product one should produce in order to maximize profits. Game theory focuses on examples where there are multiple strategic actors. My profits depend not only on the quantity that I produce, but also on the quantity that you produce. The Holy Grail of Game Theory is find a "equilibrium". An equilibrium is a stable point in the system. Neither player will have an incentive to change their strategy. If the equilibrium is stable, the system will converge on this point.

 

If we return to bridge, I think that a number of different bidding eco-systems have evolved over time. Case in point: Traditionally, there have been some very significant differences in the definition of a direct seat double between Europe and the United States. In the US, a double of a 1♥ opening is "takeout". In much of Europe (Italy especially) the double was much more nebulous and included a much wider variety of hand types. There are a number of possible explanations for this difference. However, I suspect that differences in definition of the 1♥ opening had a significant impact.

 

Here once again, I suspect that the topic area being discussed is far too broad to reach anything approaching consensus. We can't even agree about what constitutes a reasonable defensive to a 15-17 HCP NT opening. I doubt that this thread is going to produce anything more conclusive than "this is complicated"

Please feel free to put whatever constraints in whatever situations you feel that would make the discussion more helpful. Richard, as always thanks for your thoughtful bridge feedback.

[Winstonm]

Big topic - no time now - will try later.

[mikeh]

Factors that I consider relevant to overcall decisions (a non-exhaustive preliminary list, in no particular order):

 

1. Space consumption: if I bid 1♦ over 1♣, then I tend to have a reasonable hand: certainly, the minimum hand for 1♦ is less than that for 1♠. Equally, while my 2/1 overcalls have significantly higher minimum requirements than my 1/1 bids, 2♣ over 1♠ is more disciplined than 2♣ over 1♦.

 

2. Lead considerations are not of huge importance to me, but I would need a decent hand to offset suit weakness if I were to bid, for example, 1♠ on Q9876 over 1♣

 

3. I am more concerned with getting into the auction than I am about reaching game or slam. Vulnerability matters, especially at imps, but while I am not insane red at any scoring, I believe that allowing good opps to have an unobstructed constructive auction dooms me to a losing or at best break-even result at all forms of scoring. This is less true at imps, since I usually play on teams where I can trust my teammates, but even there, I'd prefer to get in and mix it up unless it looks suicidal.

 

4. I like to play a decent structure over my overcalls: transfer advances, fit-showing jumps, mixed raise jump cues, etc... to recover a bit of the science that the opps have taken away by their opening

 

5. I am a very wide range overcaller... I agree with Kokish in this. My doubles and bids are slightly stronger, as a minimum, than opening a suit and jump-rebidding. I will do it on the right 16-17 count if my suit is ♠s, since I can usually control the auction, but I have, without the slightest qualm, overcalled in a minor with 19 hcp. My doubles always allow partner to be aggressive with an unbid major: if I don't fit that (and I can't recall a hand on which I did not have tolerance or better and made a double) then I can handle the auction.

 

6. If the opps have bid and raised, 4th seat's overcall may be razor-thin if nv.

 

7. If the opps have opened and responded, 4th seat's overcall is based on good internal texture in a long suit or on a good hand. Thus 1♣ P 1♠ 2♥ could be KQJ9xx in ♥s and not much else.. especially if the hand is wrong for a 3-level adventure at the prevailing vulnerability.

 

 

Imps changes the degree of aggression, especially with respect to internal texture and length. An opp will rarely pass a reopening double of 2Major with A432 but will be happy to do so with AJ97.

 

Richard's point about needing to consider the opps' structure is valid, altho that doesn't usually affect my approach after a natural 1-level opening, no matter if that be known to be, say, 8-15 or 11+ or 13+ etc. Where opps' methods do dictate my methods, it is because they are employing some degree of artificiality.

[jtfanclub]

MikeH:

 

Space consumption: if I bid 1♦ over 1♣, then I tend to have a reasonable hand: certainly, the minimum hand for 1♦ is less than that for 1♠.

 

You meant more than that for 1♠, right?

[mikeh]

MikeH:

 

Space consumption: if I bid 1♦ over 1♣, then I tend to have a reasonable hand: certainly, the minimum hand for 1♦ is less than that for 1♠.

 

You meant more than that for 1♠, right?

yes ;)

[dake50]

The Overcall Structure of Hodges/Twineham/Fouts/etal have strategy mostly correct. The overarching defensive need is to obstruct, so devote most bids there. Leave a few bids for compete/construct. Game Us is about 8%, not 58% of hands as after opening.

Especially opponents 1C on 2-7C, 0-5D, 0-4H, 0-5S, 12-21hcp! Nothing is nailed down AND their hope is space to clarify -- take that space!! Play to induce their over-/under-/mis-bid.

Vs 1D=4+D(even better if 3cD), their hope is to find 8cM fit, take space often wins.

Vs 1M=5cM, the likelihood of their mis-bid is very low(the very justification for 5cM) so induce over-/under-bid.

[inquiry]

In this post, the opponents have opened at the one level and either we are in the direct overcall seat or responder has bid something and we are now in 4th seat.

 

Many issues to consider here:

1) constructive overcalling vs destructive.

First, I have a personal phylosophy that drives my decisions. The first, is I don't play DESTRUCTIVE methods vul versus not vul (consider this for imps, this is somewhat less clear at matchpoints). So jump overcalls at those colors are, good hands and good suits, I will MAKE it most of the time. Second, not-vul versus vul, I try to be very destructive (better to say undisciplined). I can be quite weak, not normalish strong preempt for jump overcalls. I can have side suits, and side winners or not. The idea is to but on pressure when they WANT to bid rather than penalize. At equal vul, I am more sound when vul, a little less sound when not.

 

That was for preemptive overcalls. For "constructive calls" I follow shape first principles. That is, my doubles show support for all unbid suits and with both majors (one five, one four) I tend to overcall the longer major and, if suitable later, make a takeout double to show the other. I will overcall four card suits at the one level, and VERY good five or modest six card suits at the two level. I use two suited overcalls (including misho-Raptor which is different from normal raptor). If 1NT is natural, I follow the same rules, however, doubling only with shape.

 

Two exceptions to double with right shape. First is balancing doubles can be off-shape as long as I have the unbid major(s), second is if my hand is just too strong that I can not "risk" a pass.

 

2) lead directing overcalls

 

I will make these, when I think my partner will be on the lead. There is little need to double to tell myself what to lead.

 

3) telling the opp where the cards are if we bid

 

If I am not preempting, and if I have strong reason to believe that we will be outbid, I pull it in and don't bid as often. The exception is for lead directing reasons, or to remove a bid I think they might want to make (like a game invite cue-bid in our suit at the three level).

 

4) Assuming the decision is somewhat close is overcalling very often superior to a takeout x especially when the auction may get competitive or we may have to make a 4 level decision? Even if we have a 2 suited hand 4-5 hand?

 

If you overcall, your partner is in the auction if he has a fit. When you double, he will probably have a known fit. Still, I overcall five card majors when 5-4 in the majors almost all the time.

 

5) Difference in Imp vs MP play?

I bid more at matchpoints. Probably why I don't do well there.

 

6) Vul

 

When vulnerably, my weak bids are less weak. My overcalls and doubles are the same. If it was constructive before, it is still constructive.

 

7) passed hand bidding

 

If partner and I are both passed hands, then I need a very good reason to bid. If I am a passed hand and both opponents and partner are bidding, new suits by me are fit showing (non-jump fit, or jump fit).

 

8) Other issues.

 

Get in and out of the auctions quickly using OBAR if the opponents bid and raise.