banzai points

[straube]

Picked up Better Balanced Bidding which was co-written by Ron Klinger. In it, they describe Banzai points which are claimed to be better than Goren when both hands are balanced.

 

Banzai pts

 

A=5

K=4

Q=3

J=2

T=1

 

I found it easier to add Goren pts and then add 1 pt for every honor (including the ten) at the end.

 

To convert Banzai pts to Goren pts, multiply by 2/3.

 

Some strange conclusions.

 

They might pass Axxx Axxx Axx xx because it only has 15 Banzai hcps which equals 10 Goren pts. They might open with QJTx QJTx KJx xx because it has 18 Banzai hcps which equals 12 Goren pts.

 

They gave lots of examples how it might be better. I was partly persuaded (especially for reaching 3N) but it seemed like Banzai pts over-corrected.

 

Thoughts? Anyone use Banzai pts?

[whereagles]

If there's one thing the 4321 scale is good for is when both hands are balanced... eheh. No need to mess it up.

[gwnn]

passing with three aces is nonsense (:

[Bbradley62]

So, the point of banzai points is to decrease the value we assign to A and K while increasing the value we assign to J and T?

[straube]

So, the point of banzai points is to decrease the value we assign to A and K while increasing the value we assign to J and T?

They say that "4-3-2-1 overvalues Aces and Kings in relation to Queens, Jacks, and Tens in balanced hands."

 

They give this real hand...

 

KTxx Qx Axx KJ98 opposite QJx AJTx T9xx Qx

 

Meckwell bid to 1N while users of Banzai pts bid to 3N.

 

Banzai evaluates as 19 pts + 17=36 or the equivalent of 24 Goren pts (i.e. a slightly aggressive 3N)

 

They give a constructed deal...

 

A9xx Axx Kxx Axx opposite Kx Kxx Axxx xxxx

 

Banzai evaluates as 19 pts + 13 pts=32 or the equivalent of 21.7 Goren pts. They feel that the first hand is not worth a strong NT but note that the field will be in 3N on this deal.

[rogerclee]

Goren + judgment > Banzai

 

I think it would not be that hard to argue Goren > Banzai, but I am very confident in the first claim.

[cherdanno]

Goren > Banzai.

[matmat]

Goren played bridge. Did Mr. Banzai?

[Siegmund]

Thomas Andrews has an article about 54321 points. Called them Cowan points, or something like that.

 

There was a case that, in a certain limited set of circumstances concerning balanced hands that are committed to NT, the 54321 approach is good. There isn't much of a case for using an extremely notrump-only hand evaluation method for the opening bid, even for opening bids of notrump.

[straube]

Thomas Andrews has an article about 54321 points. Called them Cowan points, or something like that.

 

There was a case that, in a certain limited set of circumstances concerning balanced hands that are committed to NT, the 54321 approach is good. There isn't much of a case for using an extremely notrump-only hand evaluation method for the opening bid, even for opening bids of notrump.

That makes a lot of sense. When you open a balanced hand you don't know whether partner is balanced or not. Three aces goes with just about anything. I'm thinking the authors make a mistake using Banzai points to open, but perhaps it has some usefulness for hand evaluation opposite an opening hand that is known to be balanced. They derived these points looking at only 4432 and 4333 hands.

 

The appendix gives some rationale for how they determined the point values. Someone ran hands for numbers of tricks and then did a least squares analysis for 5 variables (the 5 top honors). They could have picked any number of variables. For the 5, they came up with 5, 3.97, 3.06, 1.93 and 0.95. I'm a bit concerned just looking at how easily these numbers can be rounded...almost like they were engineered.

[jjbrr]

taking tricks is where the money's at

[Cascade]

Thomas Andrews has an article about 54321 points. Called them Cowan points, or something like that.

 

There was a case that, in a certain limited set of circumstances concerning balanced hands that are committed to NT, the 54321 approach is good. There isn't much of a case for using an extremely notrump-only hand evaluation method for the opening bid, even for opening bids of notrump.

Richard Cowan is a mathematician/statistician at the University of Sydney. Possibly retired now.

 

You can see a summary of his original analysis here

 

54321 count

[kenrexford]

I have always felt that notrump game contracts fall into one of two main categories. I call them T and Cloud.

 

A "T" notrump contract is one with a long suit to establish (the stem of the T) and stoppers in the various suits (the top of the T). 4321 seems to under-guess a T 3NT, but adjustments help. Looking for long suit adjustments and controls adjustments.

 

A Cloud notrump is one where you end up with 9 before they end up with 5, but a lot of work needs to be done, in a lot of suits. These contracts often can be set double dummy, and these sometimes fail if you miss the line. Banzai Points might in theory better handle Cloud notrump contracts. Not sure.

[gwnn]

The appendix gives some rationale for how they determined the point values. Someone ran hands for numbers of tricks and then did a least squares analysis for 5 variables (the 5 top honors). They could have picked any number of variables. For the 5, they came up with 5, 3.97, 3.06, 1.93 and 0.95. I'm a bit concerned just looking at how easily these numbers can be rounded...almost like they were engineered.

1.03

0.91

1.13

0.98

0.95

 

For the additional utility (I know there's a neat word for this in economics...) of each honour. I feel pretty surely that this should be a monotonous series, not something that has been arbitrarily perturbed from a bunch of ones.

[ONEferBRID]

I ran across this one sometime ago:

 

A = 4.5

K = 3.25

Q = 1.75

J  =  0.5

       10

- - - - - - - - - - - - - - - - - - - - - -

So...for example, that relatively balanced 18 point hand that I posted in the 2/1 forum ( Rebid --Part 1 ) would upgrade to 20 ( 3 Aces and 2 Kings ) to help "justify" a 2NT opening.

[straube]

Thomas Andrews has an article about 54321 points. Called them Cowan points, or something like that.

 

There was a case that, in a certain limited set of circumstances concerning balanced hands that are committed to NT, the 54321 approach is good. There isn't much of a case for using an extremely notrump-only hand evaluation method for the opening bid, even for opening bids of notrump.

Richard Cowan is a mathematician/statistician at the University of Sydney. Possibly retired now.

 

You can see a summary of his original analysis here

 

54321 count

I think his study is flawed. He broke the problem into looking at trick expectation for individual suits. That likely doesn't take into account the frequency that 2-2 vs 3-2 vs 4-4 etc actually occur. It doesn't take into account defensive help. It undervalues aces for the control they give; we're not playing each suit one at a time...we're trying to play our suits and not their suits. It doesn't take into account that honors can be guards...unable to take tricks if we lead the suit but able to take tricks if the opponents do so.

 

He ought to instead have looked at actual deals, recorded how many tricks were taken and then solved for the top 5 honors.

[3for3]

It is like real estate, location*3

 

Jacks and Tens in insolation are of dubious value. Add them to a Queen and they are clearly more value than Goren.

 

ATx

Jxxx

KQx

AQx

 

Versus

 

Axx

QJTx

KQx

Axx

 

Surely the second hand isfar better than the first.

 

In other words, J/T are more context dependent than the higher honors.

 

Danny

[babalu1997]

all counting methods start with aset of hands which justtify their creation

 

like ltc, then there are adjustment

 

like ltt for contested auctions, then there are adjustments

 

like ahen, goren points, then there are adjustments

 

points, schmoints

 

use your brain space for other things

[NickRW]

Constructed examples prove pretty much nothing. 54321 will work well enough for you in *some* low level NT contracts - the "cloud" type that Ken mentions, but it is diabolical for higher level and suit contracts.

 

Nick

[Cascade]

Thomas Andrews has an article about 54321 points. Called them Cowan points, or something like that.

 

There was a case that, in a certain limited set of circumstances concerning balanced hands that are committed to NT, the 54321 approach is good. There isn't much of a case for using an extremely notrump-only hand evaluation method for the opening bid, even for opening bids of notrump.

Richard Cowan is a mathematician/statistician at the University of Sydney. Possibly retired now.

 

You can see a summary of his original analysis here

 

54321 count

I think his study is flawed. He broke the problem into looking at trick expectation for individual suits. That likely doesn't take into account the frequency that 2-2 vs 3-2 vs 4-4 etc actually occur. It doesn't take into account defensive help. It undervalues aces for the control they give; we're not playing each suit one at a time...we're trying to play our suits and not their suits. It doesn't take into account that honors can be guards...unable to take tricks if we lead the suit but able to take tricks if the opponents do so.

 

He ought to instead have looked at actual deals, recorded how many tricks were taken and then solved for the top 5 honors.

I am not sure what was done but he may well have taken into account the relative frequencies of those suit lengths:

 

"I found the best values for the honour cards by a weighted least squares analysis" - my emphasis.

[Siegmund]

Bear in mind he published in 1987, and analyzing even moderate numbers of hands in automated fashion wasn't really a viable approach until the mid-90s. He would have HAD to either address a simplified tractable form of the problem (suit combinations), cherrypicked hands from many years of published tournaments with table results, or made some other kind of assumption we'd find unacceptable now.

[stegenborg]

Hi

 

Thomas Andrews have a lot of material about various point counts here:bridge.thomasoandrews.com/valuations/

 

I think he finds this to be quite good:

A: 4.2

K: 2.8

Q: 1.8

J: 1.0

T: 0.4

 

Another good alternative is probably this:

A: 4.4

K: 2.8

Q: 1.6

J: 0.8

T: 0.4

 

I have actually seen the last one on the convention card of a bunch of players in Oslo, but as 11-7-4-2-1.

 

Most of us are probably best of using 4321 plus a little judgement, including appreciating aces and tens.

 

Regards

Stegenborg

[Echognome]

1.03

0.91

1.13

0.98

0.95

 

For the additional utility (I know there's a neat word for this in economics...) of each honour. I feel pretty surely that this should be a monotonous series, not something that has been arbitrarily perturbed from a bunch of ones.

Neat Economics Word = "marginal"

Neat Mathematics Word = "monotonic"

 

Main Entry: marginal utility

Function: noun

Date: 1890

: the amount of additional utility provided by an additional unit of an economic good or service

 

Main Entry: mo·not·o·nous

Pronunciation: \mə-ˈnä-tə-nəs, -ˈnät-nəs\

Function: adjective

Etymology: Greek monotonos, from mon- + tonos tone

Date: 1776

1 : uttered or sounded in one unvarying tone : marked by a sameness of pitch and intensity

2 : tediously uniform or unvarying

 

Main Entry: mono·ton·ic

Pronunciation: \ˌmä-nə-ˈtä-nik\

Function: adjective

Date: 1797

1 : characterized by the use of or uttered in a monotone

2 : having the property either of never increasing or of never decreasing as the values of the independent variable or the subscripts of the terms increase

[jacksond]

The hand QJ10, QJ10, QJ10, QJxx

much maligned in another thread as hardly worth an opening bid never mind a strong NT in Banzai. It is 23 points in Banzai

 

Well suppose you find yourself playying in 3NT with

 

Axx, Kxx, Kxxx, xxx opposite the above hand.

 

Obviously not a contract of great beauty but it has some genuine chances and certainly if the defense loses a tempo on opening lead there are plenty of potential tricks available.

 

By contrast if partner has opened A strong NT on

Kxx, Axx, Axx, Axxx. A real strong NT pre Banzai then I think you have nearly zero chance of making 3NT with the A K K hand

 

certainly i prefer the hand with the queens, Jacks and Tens if I get to 3nt with Axx, Kxx, Kxxx, xxx

 

incidently i thinlk we all know 4333 hands are a negative and holdings such as KQ bare or QJ10 are small negatives so in any point count method one is entitled to upgrade or downgrade a little from the basic point count.

 

Lets see some example hands please rather than opinion where you think the 54321 method doesnt work and we can give our views

[Vampyr]

Poor old Milton Work.