bab9

In order to help understand bidding and hand evaluation better, I have been trying to locate how the point count system came about, and the assumptions behind its development. So far all I've found it that there are a number of different point count systems, for example: milton point count, work point count, robertson point count, karpin point count, zar points, etc, each with a different point count allocation to high cards and distribution. I understand that a lot of these systems are refinements on other systems based on the authors experience. My question relates to the base system they all came from. How did the original point count system come about? What made the author decide on the 4321 construct? What assumptions were made to come up with the system, eg: 4/5 card major, distribution of missing cards, etc.

I have recently gone through this experience, from the learner perspective. My partner developed a system and documentation to go with it. However, over the years the system had changed and not all relevant sections of the document were updated. As a result the documentation contains inconsistencies in bid meanings. All I can suggest is that if you give him/her any reference material to learn the system, make sure it is all consistent with the current version of your system.

Thankyou. Hopefully these books explain why you are required to discard in a particular way: advantages and disadvantages. Not yet found the link on Slavinsky signals. I recall reading a post on BBF that Prism signals were illegal as they were classed as encoded signals. Is this the case, or can you use them in events?

Given that there is bidding theory, is there also discarding theory? I am aware that there are a number of discarding systems: odds/even, high/low, McKenny, are these based on some sort of discarding theory? If so, can you direct me to a book on the subject?

Free, Quick recap, Dirk indicated that he was looking at the bidding when only 3 bids were used to find the right suit contract, ignoring HCP for the time being. There were two other systems briefly discussed, one being a binary decision tree and the other referred to as the silent spade system (is there any update on this?). I was asking about the 7 card fits (did not mean to imply that Dirk was specifically looking at this situation) to see how the program handled those decisions where there is a choice between 2 suits and NT (a followup to some of my previous inquiries). Dirk, I was not aware that the program was weighted for 8+ card fits (weighting for major is fair enough). Two things: 1. If you were to look at hands with just 8 card fits, do you see the simulation preferring 4/4, 5/3, 6/2 fits? 2. Do you have a weighting for NT? If so, how is it implemented?

Dirk, You mentioned that it rarely uses more than 5 opening bids. Are these opening bids simulation dependant? If you have two 7 card fits, is the simulation likely to find the higher suit for the contract or NT? Given HotShot's examples, it is likely that the range of opening bids may change when HCP are taken into account. As a result, you may not need to rebalance the weights at this stage. Looking again at the previous results we seem to have to bidding sequences that give the same result. 1♦ - 1♥ and 1♦ - 2♣ (realise there is only 1 example) both show responder is balanced. It might be worth looking at the weights on the responses to ensure no two sequences give the same information. Alternatively, there may be something subtle going on here that may be interesting to look at.

Reading this book at the moment. It is changing how I look at and play pre-empts.

Dirk, As the results do not relate to the first table of results, the meaning of the opening bid is unclear, and hence how the bids combine is unclear. However, it is very interesting that certain sequences do not occur, eg 1♣-2♣. This could open up to having additional conventions added to the system that do not result in the loss of a 'natural' bid. I noticed there were no 1NT or 2 level openings in this run. Was the system generated with the same hands as the previous system you posted? In the bidding sequences, how often did the 3rd bid choose the correct suit/NT contact? Did the simulation choose the longest combined suit, or did it somehow give preference to the majors? It is interesting that the simulation was able to find a transfer method in the majors over a 1♣ opening. Given that the system changes each time it is run, I would be interested in seeing the results of each run that you have time to extract the information. Barry.

Dirk, Interesting results. Are you able to determine how the responding sequence might proceed after the opening bid?

Most beginner courses also push the concept that the trump suit should be a suit in which you and your partner have a known fit. And a lot of books claim that a 4/4 fit is superior to a 5/3 and 6/2 fit. Point 3 of my post addressed how the declarer may have concluded there was a fit with partner. I am disappointed to see that it seems this thread is more about a flaming then bridge.

As a B/I player, I must be missing something (I am not referring to the implication of possible cheating, but the bid itself). The reason being the rules of thumb that I was taught. 1. The declare has a 3 loser hand. I was taught to expect 2 tricks from your partner. Hence would make the contract at the 6 level. 2. If you have a solid suit, it is best not to make it the trump suit as once the trumps are drawn it will generate clear winners. A possible explanation why ♦s were bid instead of ♣s. With the length of the ♣ suit, the declarer could dump losers. 3. After the 3♠ opening, it is likely that partner is short in ♠, and hence has support for the other suits. Given that declarer has a long suit in ♣s and RHO has a long suit in ♠, this leaves the likelihood that partner will have a red hand; with ♦s being declarers better red suit. I have seen no mention of the system the declarer and partner play. a. Do they play canape bids? b. Is a double of 3♠ for takeout or penality? Also, what system are the opponents playing. More specifically, what was the explanation / meaning of 3♠. What was the vulnerability of the hand?

Should we be looking at "interference"? Would we be simplifying the initial development if we looked at something like the sequence (1♥) - P - (2♥) - ? and have the computer/system determine the best bid? In which the 1♥ and 2♥ bids can be well defined, say using SAYC. I recently read that the idea of "support" is based on the law of total tricks. It would be interesting to see if a computer would base support on a similar method, or have another determinant to indicate support. With the work done on the neural networks so far, are you in a position to indicate if a response to an opening bid can should support? Either in a natural or artifical sense.

As an idea what if instead of using 1 neural network, a different one was used for each round of bidding? Kind of getting each neural network to specialise in a particular round of bidding. There would be a strong agruement for having information from the previous neural network feed into the current one.

Unexpected results should not be classed as a failure. How did you determine that you could not teach the program anything? What type neural network did you use? How many nodes? How big was your data set? Were you looking at all bidding situations, or just uncontested ones?

Okay, here's an interesting thing that I noticed about this. Look through the tree at all the places where it asks for information about the same feature twice (It asks about spades when it already asked about spades previously). I count 32 times where this happens. In 23 of those cases (72%) the question was asked again when a low answer was given to the first question. So "I'm weak" "Really? How weak?" was more common than "I'm strong" "Really? How strong?" Same with "I have short spades" "Really? How short?" Is this an artifact of the setup, or is there more value in telling partner what you don't have? Tysen I have read about conventions that look later in the auction at first round controls and then ask the question is this due to an ace or a void. One implication of the decision tree may be the asking/giving this shortage information eariler in the bidding process. Perhaps there is a lot of value telling partner what you don't have, given that conventions have been developed to show shortage, eg splinters.