mikeh, on Aug 9 2007, 03:03 PM, said:
<snip>
2. I agree with your description of the goals, and excuse me for a possibly poor use of the term fibonacci analysis: my partner was the math major/computer whiz who designed the system. <snip>
I certainly would not recommend our method for anyone other than a work-alcoholic. I don't regret the work at all: it was a lot of fun, and when we were 'on' we were a pretty formidable partnership. <snip>
Mike,
I probably did post this with the correct language. My point was not to find fault with your terminology, but rather to say that the concept isn't as complicated as it is often made out to sound. I know *you* understand the concept, but I'm going to post the logic behind it for those that do not.
Imagine that we have a set of possible hand types. Typically these types are in the form of hand shapes. For example, one hand shape might be 4=1=5=3 and another 4=3=1=5. In order to show each of these hand types, we need at least two bids (one for each shape) if we want to show this exactly. We often call this a "full" relay. If we only want to show that the pattern is, say 4=x=5=y, where x and y could be any length, then we have a "partial" relay. Either way, the number of types of hands we can show depends on how much bidding room we have left below a given level (which I'll set at 3NT as it's the most common one).
So imagine that we have described our hand up until now and the next asking bid (relay) from partner is going to be 3NT. Obviously, since partner asks with 3NT we have no room to describe any hand types, so we assume only the 1 hand type is shown. If partner asks with 3
♠, we have a similar problem. We can only bid 3NT (and stay at or below 3NT). But suppose now that partner asks with 3
♥, then we can bid either 3
♠ or 3NT. That is to say, we can now show 2 hand types. If partner asks with 3
♦, then we can show 3 hand types: one each for 3
♥, 3
♠, and 3NT. However, the complexity goes up when partner asks with 3
♣. Why? Well we can group together more than one hand in our 3
♦ response, since partner can make a further ask with 3
♥. Thus we can put 2 hand types in the 3
♦ response and 1 each in the 3
♥, 3
♠, and 3NT response, for a total of 5 hand types. If we carry this on, we get:
Ask #Hand Types
3NT---1
3
♠---1
3
♥---2
3
♦---3
3
♣---5
2NT---8
2
♠---13
2
♥---21
2
♦---34
2
♣---55
1NT---89
This sequence you will not is one where the next value in the sequence is the sum of the two previous values. (3 = 2 + 1, 13 = 8 + 5, etc) That sequence is known as the Fibonacci sequence. It is useful for planning how much information you can extra at a given level. Thus for Mike and his partner, if they use 2
♣ as their relay after 1M, they can show 55 types of hands at or below 3NT. If they used a 1NT relay instead, they could show 89 hand types. It actually gets more useful than that. Suppose they do use 2
♣ as their relay. They can go further with the classification. As those 55 hand types can be broken down as follows:
2
♦ - Can hold 21 hand types
2
♥ - Can hold 13 hand types
2
♠ - Can hold 8 hand types
2NT - Can hold 5 hand types
3
♣ - Can hold 3 hand types
3
♦ - Can hold 2 hand types
3
♥/
♠/NT - Can hold 1 hand type each
For a total of 55 hand types. So the subsequent sequences are also Fibonacci. I measure how efficient my relay systems are by seeing how much of a load each of the "buckets" holds. Maybe I'll put 20 hand types in my 2
♦ bid, 11 in my 2
♥ bid, 8 in my 2
♠ bid, etc. That tells us how much use we are getting out of each bid.
I guess my point is that designing the relay can be fun and makes you think of how much information you can share. Maybe your goal is not to divide everything by full shape, but rather partial shape and also some measure of strength or controls. At least you can figure out how much you can describe.