"probabilistic" opening bids

[semeai]

We're discussing two types of randomization methods here:

 

1) Those due to shuffling your hand. For example, gombo121's first mention of this with red = 0, black = 1 (which suffered from being correlated with hand type), my suggestion using an absolute order of the cards to read off a permutation of the 13 cards, and hrothgar's suggestion of using transitions to get bits. The latter two have no correlation with hand type/strength. (I happen to prefer mine, as it contains much more info as well as being better suited to getting probabilities with denominators not a power of two, but the bits from transitions should be okay too. Really it's just a special case that records a manageable amount of data.)

 

2) Deterministic ones based on the cards you hold, such as gwnn's suggestion of adding up the spots and taking the remainder modulo something and lamford's suggestion of using whether you hold a 2, whether you hold a 3, etc.

 

Is there a regulatory issue with either one? It seems unlikely, but (1) could be ruled as using an outside aid (though it seems just to use the cards) or as being impossible to disclose (though I think it should be fine just to tell what the method is). It also seems unlikely, but (2) could be disallowed for being encrypted (though partner doesn't have the key).

 

If there's no regulatory issue, I don't know why you wouldn't use one of the uncorrelated methods from (1). Also, methods that use shuffling but have a correlation with hand type/strength seem strictly worse than either uncorrelated ones from (1) or (minimally) correlated ones from (2).

[Vampyr]

If there's no regulatory issue, I don't know why you wouldn't use one of the uncorrelated methods from (1). Also, methods that use shuffling but have a correlation with hand type/strength seem strictly worse than either uncorrelated ones from (1) or (minimally) correlated ones from (2).

 

Clearly the order in which the cards are picked up could create a more-or-less "random" situation, whereas methods based on one's actual holding are clearly not, as they are, after all, based on your hand. It seems to me that this kind of treatment is legal, as long as you disclose to your opponents your method of randomising/choosing.

[semeai]

It seems to me that the order in which the cards are picked up could create a more-or-less "random" situation, whereas methods based on one's actual holding are clearly not. It also seems to me that this kind of treatment is legal, as long as you disclose to your opponents your method of randomising.

 

You don't have to do it based on how you pick up your cards, which could be influenced by the previous table's shuffling or lack thereof. You can shuffle them before you look at them. Of course if you're doing this every board (so as not to give away when your hand requires a random number to help decide your bid) it might get tiresome.

[lamford]

(2) could be disallowed for being encrypted (though partner doesn't have the key).

Even if the opening bid is decided to be encrypted, and I do not think that is the meaning of encrypted, ANY defence to a two-card club opening is permitted, even in a novice event, so it can be used as an overcall. A 1NT overcall of a 2-card club suit, stating "I'm present at the table",, is allowed at level 2.

 

So you might disallow it in a 192-board brown sticker event as an opening bid, but it is still legal in the EBU over a short club in the Palmer Bayer (a supposed No-Fear event).

[Free]

snip

[Finch]

A much better method of randomising an opening bid, which you can disclose easily to opponents, and will have considerable advantages in the play, is the following, which we employ against strong clubbers, where ANY defence is permitted:Bid Description Frequency1NT Any deuce 0.6961S Any trey 0.2121H Any four 0.0641D Any five 0.020The lower card takes priority for deciding which bid to make. So 1D means you have a five, but no card of lower rank. There are many advantages when defending because you know, if your partner overcalls 1S, he has no deuce and at least one three, so information may be available to you but not to declarer. You need to be careful playing the card you are known to have sometimes! This method is, bizarrely, allowed over a two-card club suit at level 2 in the Newbridge Novice Pairs under Orange Book 11M2. Disclosure under OB10A6 can certainly be full and frank. I think it is Brown Sticker for an opening bid, however.

 

 

Even if the opening bid is decided to be encrypted, and I do not think that is the meaning of encrypted, ANY defence to a two-card club opening is permitted, even in a novice event, so it can be used as an overcall. A 1NT overcall of a 2-card club suit, stating "I'm present at the table",, is allowed at level 2.So you might disallow it in a 192-board brown sticker event as an opening bid, but it is still legal in the EBU over a short club in the Palmer Bayer (a supposed No-Fear event).

 

Is there some reason you needed to post this twice?

I think it is more surprising that you are allowed to open a suit that may only have 2 cards in it at level 2. If you aren't happy with highly conventional defences to your methods, play natural opening bids. No 'novice' or 'no fear' player should ever have to worry about coming up against random defences, because they can play a simple system instead.

[gordontd]

Even if the opening bid is decided to be encrypted, and I do not think that is the meaning of encrypted, ANY defence to a two-card club opening is permitted, even in a novice event, so it can be used as an overcall. A 1NT overcall of a 2-card club suit, stating "I'm present at the table",, is allowed at level 2.

 

So you might disallow it in a 192-board brown sticker event as an opening bid, but it is still legal in the EBU over a short club in the Palmer Bayer (a supposed No-Fear event).

The Palmer Bayer is a simple-system event that doesn't allow short club openings. I hope you and Bob Brinig didn't break the rules when you won it, Paul!

[helene_t]

zip

[Zelandakh]

Is bridge not one of the few games where coming up with an almost completely accurate RNG for 20% actions is possible? When you first pick up your hand, shuffled naturally, observe the first card between 2 and 6 and compute its remainder (or subtract 1 of preferred). If no card between 2 and 6 is held then use 7 to jack instead (remainder or subtract 6). You can use the remainder from the last board as the check digit - if they match then take the 20% action. Alternatively you could take a decahedral die with you and roll it between rounds out of sight of anyone else. As for the concept, seems perfectly legal to me - many systems have more than 1 bid to describe a given hand type.

[nige1]

Sorry, my post may flout IBLF guide-lines. Anticipating another deletion, I've reposted to "General bridge discussion" :)

[Finch]

As for the concept, seems perfectly legal to me - many systems have more than 1 bid to describe a given hand type.

 

While the concept seems legal to me as well, in practice simply stating 'we bid at random' is frowned on by regulators, because there is always the suspicion that you don't - you have some (possibly even subconscious) way of deciding which bid to choose. If you have a declared algorithm for selection which action to pick I think you'd be OK.

 

There's an English pair whose method of choosing which minor to open with 3-3 or 4-4 is carefully documented on their card and is something like (i) choose the better one if there is huge disparity between them, otherwise (ii) count the number of odd pip cards in the minor suits and open 1C if this is even, 1D if this is odd. {pips = cards from 2 to 9 inclusive}

[lamford]

The Palmer Bayer is a simple-system event that doesn't allow short club openings. I hope you and Bob Brinig didn't break the rules when you won it, Paul!

We played 5-card majors with better minor, although we did meet one pair that played 5-card majors and a 4-card diamond suit and 3-card club suit. I got a blank look when I asked what they did with a 4-4-3-2 hand outside their no-trump range. Some simple-system events provide a convention card from which you cannot vary, and I see now that London does so for the Palmer Bayer; my error. However, some simple system events permit a short club under OB9D9. I presume that any defence is permitted to those under 11M2.

 

And, for the record, Brinig and I were invited to play in the event by the organiser.

[Vampyr]

If you aren't happy with highly conventional defences to your methods, play natural opening bids.

 

This is easy to say, but the problem is that five card majors with a 2-card club suit is all the rage in London lately. So lots of people are playing this method who have no notion that any defenses are permitted. Not playing a short club myself, I have no way of knowing how many people have taken advantage of this regulation in designing their system; but I know a few who have, myself included. So a hapless prepared clubber is liable to find herself overcalled with a bid that has a seemingly random combination of possible meanings, and is very difficult to counter.

 

I think that the regulations are sensible, but there is little awareness among 2-card clubbers that they are playing a highly artificial method. It seems to me that many people consider this method fairly standard and natural.

[blackshoe]

It is interesting that people often consider what they play "standard". It is even more interesting that they consider things that are "standard" to be "natural".

 

Perhaps we need a vocabulary test for bridge players. ;) :D

[Vampyr]

It is interesting that people often consider what they play "standard".

 

Well, a lot of people play what is popular in their area, by definition. So people in different clubs, geographical areas etc will all be playing what can be considered a "standard" system, though between the groups there may be hige variation.

 

It is even more interesting that they consider things that are "standard" to be "natural".

 

Or the other way round. Sometimes people playing standard discards will say "natural".

 

But in general, people who play natural systems, and my specific experience here is in an Acol culture, consider other natual systems to be more "standard" than systems with lower-level artificial opening bids -- typically, around here, strong club or Polish Club. So at least here, a standard system is a natural system. Thus shifting to 5-card majors does not seem like an earth-shattering change, and shifting to a 2-card club suit (usually to keep diamonds as 4, but sometimes also unbalanced) may feel like a reasonable consequence of this. But this shift makes a world of difference in how the system is classified and what defenses can be used against it.