jogs

True. The main argument for responding with 6 points is one must keep the bidding open for partner. In this auction partner will get another chance. Also all those 6 point responses are on the one level. Qxxxx, Kxx, Jxx, xx Do you really need to bid 2♠ with this crap? Qxxxx, KJx, Jxx, Jx I would also pass this hand. 2♠ shows 8-11. That doesn't mean one is required to bid with 8. It means if he does bid he may have as little as 8. KQTxx, xxx, Kxx, xx

Quotes from link. Disagree with his ranges. With a 5 card suit, NF is made with 8-11. Double then bid suit is an opening hand. Opener must raise with 4 card support, even with minimum. Bid 3♠. Play fit showing jump shifts. Forcing to original suit if made by a non passed hand.

The ♥A isn't carrying full weight on offense. Axxxx, x, x, AQxxxx Most of this board would choose to bid with this hand.

The 4531 and 4513 patterns play about a half a trick better than the 4522 pattern. Do any of the top pairs account for this? 4531 open 11-15. 4522 open 12-16. The half a trick is more like 1.5 points better.

Stop assigning blame. The purpose of the post mortem is to learn to stop repeating the same mistakes.

The point is the estimator isn't linear. It isn't a straight line. It is more like multi-dimensional blob. It isn't only our honor count that matters. The location of those honors and whether they are working together also matter. During the initial evaluation of the hand there is no need to be precise. Bissell points and workcount are just loose guidelines for valuation. I use Milton Work HCP because of ease of calculation. Other methods are much harder to calculate. Have never seen evidence any of those methods are more than a small marginal incremental improvement. The variance of the calculations from those methods are just as large as the variance of workcount. Assuming we are dealer, what do we need to know? First, whether or not to open. If we decide to open, what to open. Why do we need a more precise valuation of our hand? During the auction when we learn more about how partner's hand fits with our hand the valuation can change dramatically. This negates the efforts of a complex initial valuation. This model is in terms of our tricks rather than my points. These hands are 10 +/- e points and this error is large. As we learn more about partner's hand the error will be reduced. During the initial evaluation, it is sufficient to know to pass these hands as dealer. E(tricks) = trumps + (HCP-20)/3 + e Std dev is about 1.25 tricks/board. E(tricks) = trumps + (HCP-20)/3 + SF + e For flat hands the std dev can be as low as 1 trick/board. This SF term is skewness/flatness as suggested by Lawrence/Wirgren. Flat boards reduce the trick estimates. Skewed boards increase the trick estimates. These two models are for fitting partner's hand with our hand. With luck we will know the value of the terms by the second or third call of the auction. These models are best for assisting the contested auctions 3 over 2 and 3 over 3. In general the flat hand should not bid 3 over 3. 5332 should rarely compete 3 over 3. ................. In another post I will introduce the other independent random variable, pattern.

retest: trying to post west/east hands [hv=pc=w&e=st842hatdkq4ck732&w=shk8732dajt97caj4]266|200[/hv]

test: trying to post west/east hands [hv=pc=w&e=st842hatdkq4ck732&n=shk8732dajt97caj4]266|200[/hv]

How did the ♥5 and ♥4 switch hands? Against Zia, you needed to open lead the ♥8 to have any chance of beating him.

This model is for suit strains and the general case. E(e) = 0, The expected error is zero. The standard deviation of the error is approximately 1.25 tricks/boards. Turns out E(e) <0 for combined trumps >= 10 or expected tricks >= 10. This model works best when the expected tricks is between 3 to 10. Our expected tricks fluctuated wildly depending on whether we declare in our suit or defend in their suit. When trumps >= 10 or expected tricks >= 10 it requires a much more complex polynomial model. For a specific board in high level auctions we should attempt to count the tricks.

POWER Power is one of two multi-dimensional independent random variables used for estimating tricks. High card point count is the main component of this estimator. Most systems treat high card points as if it were the estimator, power. The location of the HCP and how honors interact are also components of the power estimator. Honors in long suits are worth more than honors in short suits. Honors working together are worth more than honors standing alone. Point count: ace=4, king=3, queen=2, and jack=1 ♠ AKQJ ♥ 432 ♦ 432 ♣ 432 ♠ A432 ♥ K32 ♦ Q32 ♣ J32 ♠ AK32 ♥ QJ2 ♦ 432 ♣ 432 Each is an example of a 10 point hand. They are obviously not of exactly equal value. It is difficult to measure the exact effects of the honors in each hand. 10 is the approximately correct value for each hand. In statistics there is the error component in every model to account for the deviations. Power is the independent random variable. High card points is the dependent variable of power which is proportional to tricks. Therefore it is easier to use HCP to estimate tricks than the actual independent random variable, power.

Waste of time. You are free to run your own test.

Already explained that from the combined tenth trump on, each successive trump is worth fewer fractional tricks than the previous trump. Also controls play a larger role on tricks in high level contracts.

Some of the readers are already familiar with this model. I have been posting this model on RGB for over 3 years. Since the beginnings of bridge most bidding systems were based on pointcount with modifications. Those bidding systems ignored the effects of trumps on tricks. Ignored how tricks fluctuate wildly depending on strain. Larry Cohen used Jean-René Vernes' discovery of the relationship between trumps and tricks to develop his total tricks model. This model combines both points and trumps to estimate tricks. This method accounts for fluctuations due to strain. E(tricks) = trumps + (HCP-20)/3 + e This model's reliability starts to break down on the four level. Lawrence/Wirgren discovered that skewness/flatness also affects tricks. In the general case flatness can reduce the estimates by one full trick. Skewness can increase the estimates by one full trick. The main drawback is one doesn't often know his partner's exact pattern. We do know when our own hand is flat tricks are reduced. Flat hands reduce expected tricks. 4333, 4432, 5332, and 5422 generates fewer tricks than the two random variable model would suggest. Even 6322 and 7222 often disappoint. E(tricks) = trumps + (HCP-20)/3 + SF + e In the general case the SF term should range from -1 to +1. The affects of SF is measured for the normalized 4-4 fit and the normalized 5-4 fit. Chart is posted on previous post #18.

test. does image work? http://jogsbridge.weebly.com/uploads/1/8/0/2/1802582/554030.jpg?617 Normalized here means each side holds 20 points.

Did you catch the psyche? Are you obligated to tell opponents of this psyche? This game claims to be full disclosure. When the Laws were first written, players were unsophisticated. Today the psyching pair has a huge unfair advantage. The easiest way to catch opponents' psyches is by partner's BIT. And that is illegal, against the Law.

Sorry, lost a minus sign. Should read y = A+B+(HCP-20)/3 + e

In poker one is allowed to bluff. Poker is not a full disclosure game. You are allowed to keep your strategy a secret from opponents. Bridge is a full disclosure game. Opponents are allowed to ask the meaning of your bid. The real problem is it is easy to field partner's psych. Opponents' BIT often give away psych. But one can't be 100% certain. Should one be required to tell opponents when we think partner has psyched?

Ignored because MikeH is clearly wrong. He thinks an additional trump is worth no more than an additional point. A trump is worth approximately one extra trick. A king is worth approximately one extra trick. A king is worth approximately 3 points. A trump is worth approximately 3 points. But all this breaks down once the estimates are 10 or more tricks. Other parameters not included in the model start playing a larger role on the estimates of tricks.

The Bridge Bulletin July 2013, Terry Feetham wrote that the ninth trump is worth 0.5 additional tricks. The tenth trump is worth 0.5 additional tricks. Disagree with Feetham. I posted. Confession. It ain't necessarily so. This model starts to break down at the four level. Controls which play a secondary role in low level contracts are a primary parameter in high level contracts. When trumps equal 8 or 9 the expected value of the error is nearly zero. The ninth trump is worth one full additional trick. When trumps >= 10 , E(e)<0. That means when we have 20 HCP and 10 trumps, our expected tricks is less than 10. The tenth trump does not produce a full additional trick. It is more than 0.5 and less than 1 trick. From the tenth trump on each successive trump is worth fewer fractional tricks than the previous trump. It should be obvious that with 20 HCP and 13 trumps, our expected tricks is less than 13. Only need to find one example where tricks are less than 13. Will never find a board producing 14+ tricks. This also means in LoTT expected tricks equal total trumps is only true when total trumps is 18 or less. When total trumps is equal or greater than 19, the expected tricks is less than the total trumps.

It may take a day or two. I will post how to calculate standard deviation on Excel. The simple lo...ng way is to post every observation on a separate line. Have separate columns for expected tricks(by model), observed tricks, and first differences. Then find the variance of the first differences. Click the fx icon. Click 'statistical' under function category. Scroll down on function name and click 'VAR'. The std dev is the square root of the variance. Will post the other way later. Requires a few subroutines.

Isn't this different for every player? Beginners might be pleased to not finish last. Others expect to win every time. Is it better to be 65% for second or 56% for first?

Are you American? Lead the one printed in BOLD print on your convention card.

♠AT987 ♥A765 ♦A42 ♣A Should be obvious the aces in spades, hearts, and diamonds are worth different values. I don't like double dummy analysis. Prefer viewing results from live play. K facing xxx in 3NT. Sometimes the opening leader with AJ752 leads fourth best. The king steals a trick. Other times partner holds Axx or Qxx. Queens generally have no value unless supported by aces and kings. AQ facing xx. That's worth 1 1/2 tricks. Qxx facing xxx. Worth zero tricks. Qxx facing Jxx. Worth one trick only when opponents cooperate. These numbers aren't tricks. They are loser points. Doesn't everyone play with a 4-4 fit in a major and 25 HCP bid game? The expected tricks is 9 2/3. Expect to make this game 45+% of the time. But it's really E(tricks) = 9 2/3 +/- 1.25 tricks. Sometimes we go down. Still next time we bid game again. We are working with statistical probability. No system will be right all the time. We are just hoping to be right more often than the other guy. ............................. Just read Terry S. Feetham's article from The Bridge World August 2006. Not familiar with Feetham's statistical methodology. It is normal to test the estimate from a model against each observed result separately. Then report the average error and standard deviation of that error. Feetham compared his estimate from his model with the average of the observed results. Those are two different methods.

It's an estimate. A king equal 3 points and is worth approximately a trick. Therefore a point is approximately 1/3 of a trick. Have run studies on 4-4 fits and 5-4 fits. The std dev for the results is around 1.25 tricks/board. When short suit totals is included in the model, the std dev is about 1 tricks/board on flat hands. Flat hands depresses tricks. Even in the general case it can be as much as one full trick less. In specific boards it sometimes can be as many as three tricks less. 5=3=3=2 facing 4=3=3=3. This pattern pair reduces tricks. 5=3=3=2 facing 5=3=2=3. If we have only 20 HCP, expect to make only nine tricks. When partner opens 1M(5-card majors), don't jump to 4M. The LAW does not protect you.