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All comments by Craig Zastera
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As to opener's 2S “reverse” after a 2/1 response, I think many (I haven't done a poll, so I won't claim “most”) 2/1 GF players would say that this does not promise extras.

The idea is that since we are in a GF, bids should describe shape without reference to strength.

This idea could be carried further, e.g. does 1S-2D-3C show extras? On this one, I think more 2/1 players would say that it *does* show extras, but I think that a significant number (but probably a minority) would say that such 3 level non-jump rebids are also just “shape showing.”

Similarly, how about a raise of responder's suit:
1S-2C-3C
1S-2H-3H
Do these show extras? Perhaps surprisingly, I think a majority play the raise of the minor as showing extras but not the heart raise.

The problem with the style where “nothing promises extras” is that the partnership may find itself uncertain whether it possesses slam level strength or not. That is one of the reasons for conventions like “serious” (or non-serious) 3NT.

The problem with the style where all rebids above 2M (except perhaps 2NT) show extras is that opener is forever rebidding 2M with all sorts of minimum hands that may be two (or three) suiters.
A 2H rebid with AQxx-xxxxx-void-KQxx after a 2D response may not appeal to everyone.
July 25, 2016
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Most 2/1 players would interpret such a jump to 3S as a splinter raise of partner's diamonds.
July 24, 2016
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Results of simulations are not “opinions”–they are facts.
July 22, 2016
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I picked 2C with “13+”, but the real criteria is whether you consider the hand a GF or not. So the exact HCP strength required will depend on your minimum requirements for opening bids and your exact shape (e.g. a partial diamond fit is better than diamond shortness).
Given that I play relatively sound openings, I might consider some responding hands sufficient to GF with only 12 HCPs.
QJTx-x-QTx-AKxxx would be fine for 2C even though only 12 HCPs.
July 22, 2016
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Steve,

Here is how your two example hands perform
in 2NT and 3NT contracts opposite
7 and 8 HCP balanced hands.

You can seen that the 3334 hand with three
tens does significantly better than the
3235 with poor spots for GAME PURPOSES

I then tested these hands in 6NT with
14 HCP balanced hands opposite.
You can see that the results are different–
now the effect of the 5 card club suit causes
that hand to actually perform slightly better
(in 6NT) than the 3334 hand with the three tens

Each result is based on a 5000 deal simulation.
All deals played from the strong hand side.
No constraints on the EW hands.

Test Hand 1: A32-J2-K32-AKQ43

7HCP: 2NT 3NT
70.34% 28.64%

8 HCP: 2NT 3NT
84.12% 48.64%

14 HCP: 4NT 5NT 6NT 7NT
98.40% 92.42% 57.56% 9.94%


Test Hand 2: AT6-JT5-KT7-AKQ3

7 HCP: 2NT 3NT
84.86% 35.46%

8 HCP: 2NT 3NT
94.64% 63.70%

14 HCP: 4NT 5NT 6NT 7NT
99.82% 96.56% 55.12% 5.06%
July 22, 2016
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Doug,
Useful to do what you did to determine what kind of (statistical) accuracy you can expect to be getting with simulations of various sizes. As your work shows, with 1000 deals simulations, you can be off by a couple of percent.
This is accurate enough to answer most questions (like the ones under discussion in this post).

But I prefer 5000 deal simulations where I expect the results to be generally within 1% of the “true” figures.
July 21, 2016
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A reason why upgrading a (good) 14 HCP hand to 15 so as to be able to open 1NT (15-17) might have more merit than upgrading a (comparably good) 17 HCP hand to 18 (so as to open 1m and rebid 2NT) is that the latter upgrade is more likely to produce an auction that gives away valuable suit-length clues to the defenders, whereas the former upgrade might lead to a more opaque auction like 1N-3N.
July 20, 2016
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Peg,
And if partner has KQJ-Qx-QJxx-Jxxx, then 3NT (and any other game) will fail despite partner's holding 12 HCPs.

The moral is that you can't determine the value of a hand by mentally creating a specific example hand where the pair perform very well or very poorly. It is too difficult to
estimate accurately the relative frequency of the “good”
vs. “bad” hands that may lie opposite.
The only way to reach a valid conclusion is to do large random simulations so that the entire range of hands that might occur (both favorable and unfavorable) will be
represented WITH THEIR PROPER RELATIVE FREQUENCIES.
July 19, 2016
Craig Zastera edited this comment July 19, 2016
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Aaron,
Just FYI, I simulated your latest example hand,
“AJxx-Qxx-Kx-AKJx”. Of course, that isn't really a hand
because “x” is ambiguous. So I chose a specific hand with
rather small spots (smaller than average random spots):
AJ73-Q63-K5-AKJ4

Here's how that hand compares to the original example
hand from this post as well as to random balanced
17 HCP and 18 HCP balanced hands when declaring
3NT opposite random 7 HCP balanced hands with no
8+ card major suit fit):

AT6-J5-K73-AKQ43 34%
Avg. 17 HCP bal hand 37%
AJ73-Q63-K5-AKJ4 53%
Avg. 18 HCP bal hand 54%

So as you can see, your latest example, even with very
poor spots chosen for the “x”s, is just about the equal
of a random 18 HCP balanced hand while the original
hand from this post (AT6-J5-K73-AKQ43) actually performs
WORSE THAN AN AVERAGE 17 HCP BALANCED HAND.
July 19, 2016
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Actually, this shouldn't be a question subject to a “vote” at all because there is an objectively determinable answer to the question. Thus, popular opinions are completely irrelevent (other than providing information about what
percentage of people have good hand evaluation skills).
July 19, 2016
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Sorry, but you are just plain wrong.

Any possible differences between double dummy analysis and actual at the table results are completely irrelevent to the type of question under investigation here.

Here, we are trying to compare the relative playing strength of a particular specific hand to average 17 HCP and 18 HCP hands. As long as we use double dummy analysis in all cases, the *relative* strength of the actual hand vs. average 17 and 18 HCP hands will be correctly reflected.

It would be different if we were trying to investigate a question like “should a certain specific hand raise a 15-17 point 1NT opening to 3NT?”
Then, you might be able to argue that just because double dummy analysis showed 3NT making only, say, 35% of the time, that does not necessarily prove that this hand shouldn't raise to 3NT because (you might argue) actual
at-the-table results might differ considerably from
the double dummy results (e.g. maybe at the table,
you would make 3NT 55% of the time due to defensive errors).

It happens that others have investigated how double
dummy analysis compares *on average* with actual at-
the-table results from tournaments (and or on-line play).

It turns out that AT THE GAME LEVEL, on average, double
dummy results are fairly close to at the table results.

AT THE SLAM LEVEL, real life declarers tend to fare worse
than double-dummy analysis would suggest.

Conversely, AT THE PART-SCORE LEVEL, real life declarers
tend to do better than their double-dummy counterparts.
July 19, 2016
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My “gut experience” opinions on these sorts of questions have gotten to be pretty good as a result of having done a lot of simulations like this in the past.
But when a particular hand becomes an issue, I still feel the need to do a simulation to verify my intuitions.

Here, I think many overvalue this hand because they are not fully appreciating the defect in the heart suit. It is easy to be impressed by the powerful clubs while overlooking the (more than) compensating weakness in the hearts.
July 19, 2016
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Perhaps your opinion would be different if you based it on quantitative analysis.
July 19, 2016
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This hand is not close to an upgrade to 18.
Opposite random balanced 7 HCP hands with no 8+ card major
suit fit, 3NT makes 34% of the time (would need to be ~50%
to merit an upgrade to 18).

With the CT instead of the ST, the hand is slightly worse–
3NT makes 31%.

With both the ST *and* the CT, the 3NT make percentage goes up to 39%, so *still* not worth an upgrade.

That doubleton HJ is a big flaw.

An *average* 18 HCP balanced hand with no 5 card major will
make 3NT opposite random balanced 7 HCP hands (with no 8+
card major suit fit) about 54% of the time

An *average* 17 HCP balanced hand with no 5 card major will
make 3NT opposite random balanced 7 HCP hands (with no 8+
card major suit fit) about 37% of the time.

So if criteria for “upgrading” to 18 is that the hand
performs closer to an average balanced 18 HCP hand than it
does to an average 17 HCP hand, it would need to make 3NT
opposite random balanced 7 HCP hands at least 46% of
the time.

So the above hand, with or without black 10(s) does not
merit an upgrade.

The above results were based on 1000 deal simulations.
For this kind of work, I usually use 5000 deals for better statistical accuracy (but takes a long time to run them).
July 19, 2016
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Reid,
For “X”, I measured 39.46% (5000 deal simulation)
For “Y”, I measured 59.26% (5000 deal simulation)

I do not claim these results are accurate to two decimal
places as shown. Probably, accurate to nearest percent.

So, one could conveniently define a balanced hand as
“worth” the equivalent of 14 HCPs if it will make 3NT
opposite random balanced 11 counts more than 50% of the
time.

This is assuming our criteria for “worth 14” is that it
performs closer to an average 14 HCP hand than to an average
13 HCP hand.
If your defintion of “14 point equivalent” is that a hand
must perform as well as or better than an *average* 14 HCP
hand, then you would require that it make 3NT about 60%
of the time opposite random 11 counts (and about 40% opposite random 10 counts).
July 19, 2016
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I would not open the North hand either and I'll bet I would have more company than some of you claim.
Consider the popular “suggestion of 22” for min. opener:
HCP + QT + sum of lengths of 2 longest suits >= 22
This hand is 11 + 1.5 + 9 = 21.5
hence, not an opening bid.

And it has additional “negative” features to discourage
a marginal opening:
* the stiff spade creates horrible rebid problems
after 1C-1S. 1NT is awful both because of the
stiff spade and too few HCPs.
2C is awful because of the poor (and short) clubs.

* opening bids have a minimum defensive requirement
as well as an offensive one. A good rule of
thumb for minimum defensive requirement is at
least 2 quick tricks, which this hand lacks.
July 19, 2016
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Leonard,
I don't think that is correct. My card says “15-17” for 1NT opening range. What does that mean in terms of more precise, scientific evaluation methods?
I interpret (define) 15 HCP balanced hands as the set of (balanced) hands which perform “close” to the mean for all balanced hands which contain 15 “actual” (4-3-2-1) points.
So I first calculate that mean performance as described previously, and perform similar simulations to determine the “performance profile” for average 14 and 16 HCP hands.

Now, since using “crude” integral point count to characterize a hand's value is required by ACBL, a hand should be considered “15 points” (as opposed to 14 or 16) if it performs closer to an average 15 HCP hand than it does to an average 14 HCP hand (or 16 HCP hand).

So when I write “15-17” on my card for 1NT range, that means that if a hand's playing strength is closer to the average of all 15 HCP hands than it is to the average of all 14 HCP hands, then it counts as a “15 point hand” and, thus, should be opened 1NT. Similarly on the upper end–if a hand performs closer to an average 17 HCP hand then it does to an average 18 HCP hand, then it is considered a “17 point hand” and included in the 1NT range.

This seems to me the most logical way to define “15-17”. I do not think that this definition would be better characterized by using fractions or “+” or “-” in my ACBL convention card description.
July 18, 2016
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I didn't want to write a book on how to determine if a hand is worth an upgrade, so I oversimplified slightly.

My actual method to determine if a 13 HCP balanced hand
deserves an “upgrade” to 14 is as follows:
1. Generate a large number of deals (say 5000) with
random 13 HCP hands opposite random 11 HCP balanced
hands with no 8+ card major suit fit.
If you want to be very careful, add constraints
to eliminate deals where one (or both) of the
opponents would likely bid something.

Use double dummy analysis to determine how often
3NT makes. Say it is “X”%. This (X) is
the NT VALUE OF AN AVERAGE 13 HCP HAND.

2. Repeat step 1, but this time using random
*14* HCP balanced hands opposite random
11 HCP balanced hands.

This time, say 3NT makes “Y”% of the time.
“Y” is thus the NT value of an average 14 HCP hand.

3. Now, take the specific 13 HCP hand under
investigation and generate 5000 more random
deals with that specific hand opposite
random balanced 11 HCP hands
(again with no 8+ card major suit fit and suitable
constaints on the opponents hands to conform to
their actual (non)bidding).
Use double dummy analysis to determine how often
3NT makes. Say it is “Z”%.

4. If Z > (X + Y) / 2, then the 13 HCP hand under
investigation merits an “upgrade” to 14.
That is, if the hand performs closer to an average
14 HCP hand than it does to an average 13 HCP
hand, then it can be upgraded.

The above procedure only evaluated the hand for NT purposes (actually for NT game purposes). To be complete,
one might want to simulate how it perfroms opposite
stronger hands (say 18 or 19 HCP) for slam purposes.
Also, one might want to consider it's potential for
supporting major suit contracts.
July 18, 2016
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I disagree with your claim that 2NT is the least of evils.
It should show more than just a balanced minimum–it says you don't have an unstopped suit. Some might even play that it shows (or suggests) only 3 clubs. 2NT “wastes” 3 steps, hence needs to carry a more specific message than just “any balanced minimum.”

I'm used to using 2D as my inverted club raise, so my previous comment that opener should rebid 2S to deny a heart stopper was based on that style. Given the inverted 2C raise, it is probably best to show stoppers up the line, so diamonds are included in the stopper search. Hence, I suppose North should rebid 2D to show a stopper in that suit
and suggest a problem in (at least) one of the majors.
Then South can continue with an economical 2H, and *now* North can bid 2NT to show a full spade stopper (and implying heart weakness).
July 18, 2016
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Personally, I would not open the North hand. It counts to
“22” (hence, usually an opener), but has that weak doubleton HJ which is a big flaw. But I realize that most modern “light” openers would not even consider passing this hand.

Given 1C, 2C inverted is clear.
But I would *not* rebid 2NT with the North hand because I
believe that call should promise stoppers in both majors.
Therefore, I would rebid 2S to highlight the lack of a heart stopper.

Now, you hamstring the auction with your “no minorwood or kickback” edict. Why the hell not? Particularly after an inverted minor start, you should definitely play one or the other of these convenient key-card asking tools. I prefer Kickback (here 4D) myself. So I play that after the auction starts 1C-2C, a 4D bid at any point by either partner is always Kickback.

After 1C-2C-2S (and no key-card ask below 4NT), I would bid 3D (establishing a GF) with the South hand.
Now North, having already denied a heart stopper, would
bid 3H to show a partial stopper (Qx, Jxx, even xxx).
Here, North is in a very awkward position over 3D. He certainly doesn't want to bid above 3NT, so 3H, 3S or 3NT would seem to be his only options. Perhaps, having already denied a heart stopper, he should now just bid 3NT to suggest his balanced minimum.

At this point, perhaps South can suspect North's heart doubleton (no 3H which would suggest Jxx or even xxx) and
opt for 6C. If this is IMPs, there is no reason at all to choose 6NT, as 6C can hardly be worse and might easily be better (a heart ruff in the short trump hand producing an extra trick in clubs).
If 4NT is a keycard ask over 3NT (seems odd to me, but then I play Kickback), South might try this as North
might hold e.g. Axxx-xx-Kxx-AQxx where 7C would be cold.
But without the ability to ask for keycards, I don't see how South can intelligently do more than bid a reasonably conservative 6C.
July 18, 2016
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