[Cascade]

hrothgar, on Jul 17 2009, 05:20 AM, said:

ArtK78, on Jul 16 2009, 07:49 PM, said:

I don't agree with your premise.

It is no doubt true that hands meeting the requirements for opening a mini-NT are more common than hands meeting the requirements for opening a traditional strong 1NT.

However, the opportunity to open a mini-NT is much less frequent, as it is far more likely that there will be an opening bid of some sort in front of the hand holding the mini-NT opener.

When one holds a traditional strong 1NT opening hand, the chances of someone else opening the bidding in front of your hand is much less.

Furthermore, the vast majority of players who play a mini-NT do so only in 1st and 2nd positions, for obvious reasons.

So, if one were to compare the number of times a mini-NT hand comes up when that hand actually has the opportunity to open a mini-NT vs. the times that a strong 1NT opening comes up and that hand has the opportunity to open a strong 1NT, I suspect that you will find the numbers to be much closer to equal than you would have originally thought.

Anyone out there willing to generate a sim (won't be home til quite late tonight)

I'd be interested in seeing

The PDF for HCPs given a first seat opening
The PDF for HCPs in second seat, conditional on a first seat pass
The PDF for HCPs in third seat, conditional on a first/second seat pass
The PDF for HCPs in 4th seat, conditional on three passes

HCP      1st seat        2nd seat        3rd seat        4th seat      
        0.44128108      0.2963114       0.17652121      0.08588631      
0       0.00365543      0.00172555      0.00036523      0      
1       0.00787954      0.00410852      0.00106063      0      
2       0.01358222      0.00772989      0.00238525      0      
3       0.02462392      0.01521253      0.00551263      0      
4       0.03847942      0.02560515      0.01079534      0      
5       0.05183734      0.03730851      0.01818958      0      
6       0.06551482      0.05059979      0.02830066      0      
7       0.08026772      0.06634884      0.04221567      0.00053485      
8       0.08894528      0.07845606      0.05632383      0.00349696      
9       0.09354203      0.08787038      0.07065839      0.01182899      
10      0.09405601      0.09376693      0.08392605      0.02804543      0.086512794
11      0.08942656      0.09436475      0.09342423      0.05166522      0.088352293
12      0.08025309      0.08943982      0.0971405       0.07782625      0.085747777
13      0.06914234      0.08109073      0.09591242      0.10181306      
14      0.05693845      0.07005879      0.08980479      0.11855111      
15      0.04424069      0.05697499      0.07855836      0.1232084       0.06085405
16      0.03313078      0.04450563      0.06553666      0.11793912      0.049505478
17      0.02363095      0.03302106      0.05166343      0.10389384      0.038255157
18      0.01604201      0.02327522      0.03840841      0.08456908      
19      0.01036278      0.01554094      0.02686502      0.06359527      
20      0.00644364      0.00996626      0.01794193      0.04498471      
21      0.00378244      0.00601313      0.01122105      0.02947541      
22      0.00209297      0.00340836      0.00657576      0.01795874      
23      0.00111366      0.00186594      0.00367143      0.01029791      
24      0.00055871      0.00094897      0.00190503      0.00548811      
25      0.00026269      0.00045504      0.00093035      0.002721      
26      0.00011735      0.00020293      0.00042178      0.00124688      
27      0.00004946      0.00008569      0.00018026      0.00054215      
28      0.00001831      0.00003241      0.00006886      0.00020692      
29      0.00000639      0.00001169      0.00002512      0.00007611      
30      0.00000213      0.00000393      0.00000823      0.00002557
31      0.0000006       0.00000116      0.00000229      0.00000671
32      0.00000024      0.00000031      0.00000061      0.00000173
33      0.00000003      0.00000007      0.00000019      0.00000034
34      0               0.00000003      0.00000003      0.00000013
35      0               0               0               0
36      0               0               0               0
37      0               0               0               0

Based on 100 000 000 hands in each column.

The first row is a separate simulation counting the number of times there was an opening in each seat.

Its not completely ideal but I based the opening or not opening decision on the following:

Open all 12 HCP

Open all 11 HCP with a five-card suit

Open all 10 HCP with a six-card suit or two five-card suits

Open all 6-9 with six spades, hearts or diamonds

Open all 6-9 with seven cards in any suit

The last column shows the relative frequencies of 10, 11, 12, 15, 16 and 17 HCP over all positions.

[Mbodell]

hrothgar, on Jul 16 2009, 07:26 AM, said:

jdonn, on Jul 16 2009, 06:07 PM, said:

Of course you are technically correct, I didn't mean to be the first to gloss over this point. However, 3 times in one session is so unlikely if you don't generally open 1NT with a singleton with enough frequency to alert it that I don't think you will be wrong once in ten lifetimes if you force such a partnership to alert / change their methods / whatever.

I'm not sure about the relative frequencies.

Mini NTs are much more common than strong NT openings. This might be enough to push things into the realm of the plausible.

I agree with your assessment that mini-nt are much more common than strong nt. Also, adding an extra point in is much, much more common too. I've played a 12-15 range and it comes up all the time, way more often than a 15-17. And I often play a 10-12 or 12-14 depending on seat and vulnerability and we bid 1nt way more commonly than I bid 1nt in my 15-17 partnerships.

If your range is 10-13 like OP, and you open balanced and semi-balanced hands nt, I think you'd find a very large percentage of your first seat auctions start with 1nt. Not as many as pass, which is like 50%, but probably something in the range of 15-20%.

[the hog]

awm, on Jul 16 2009, 03:36 AM, said:

Stephen Tu, on Jul 15 2009, 02:43 PM, said:

Well I do.  I don't think they should be in the business of legislating what constitutes "good bridge".  If people get good results from opening 1nt with small singletons, they ought to be able to do so IMO.  It's a natural NF bid!  Nor should they be prevented from getting the bad results.  People should have the right to be crazy, as long as they disclose.

Every argument you've made here would seem to apply equally well to a 2♥ opening showing a weak two in either major. Some people think this method is "good bridge" and as long as they disclose, why shouldn't they have the right to be crazy? The bid's even "natural" in the sense that partner will often pass it and it expresses a willingness to play 2♥ opposite a (semi)-balanced hand without much in the way of values.

Of course, if you agree that 2♥ showing a weak two in either major should be allowed in all events and that ACBL (or WBF for that matter) shouldn't be in the business of legislating whether this convention constitutes "good bridge" then you're entitled to your opinion -- but you should recognize that this opinion differs from that of the vast majority of bridge players.

Really Adam? Can you please prove this claim? If not, why make it? Are you aware that some of the world's best players used this opening?

[hrothgar]

Cascade, on Jul 17 2009, 10:17 AM, said:

Based on 100 000 000 hands in each column.

The first row is a separate simulation counting the number of times there was an opening in each seat.

Its not completely ideal but I based the opening or not opening decision on the following:

Open all 12 HCP

Open all 11 HCP with a five-card suit

Open all 10 HCP with a six-card suit or two five-card suits

Open all 6-9 with six spades, hearts or diamonds

Open all 6-9 with seven cards in any suit

The last column shows the relative frequencies of 10, 11, 12, 15, 16 and 17 HCP over all positions.

Thanks Wayne

Just to make sure I'm reading things right, it looks as if the ratio of

Frequency of a 10-12 NT opening : Frequency of a 15-17 NT opening is ~ 26 : 15

From the looks of things, one could achieve an even higher frequency if you chose

10 - 12 in seats 1-3 and then switched to 14-16

[Cascade]

hrothgar, on Jul 17 2009, 09:40 PM, said:

Cascade, on Jul 17 2009, 10:17 AM, said:

Based on 100 000 000 hands in each column.

The first row is a separate simulation counting the number of times there was an opening in each seat.

Its not completely ideal but I based the opening or not opening decision on the following:

Open all 12 HCP

Open all 11 HCP with a five-card suit

Open all 10 HCP with a six-card suit or two five-card suits

Open all 6-9 with six spades, hearts or diamonds

Open all 6-9 with seven cards in any suit

The last column shows the relative frequencies of 10, 11, 12, 15, 16 and 17 HCP over all positions.

Thanks Wayne

Just to make sure I'm reading things right, it looks as if the ratio of

Frequency of a 10-12 NT opening : Frequency of a 15-17 NT opening is ~ 26 : 15

From the looks of things, one could achieve an even higher freqeuncy if you chose

10 - 12 in seats 1-3 and then switched to 14-16

Yes.

The numbers would be slightly different since i would have to redo the simulation for opening all 10-11 Balanced.

[ArtK78]

The simulation shows what we all knew to be the case: Balanced hands with 10-12 HCP are far more common than balanced hands with 15-17 HCP.

That is not the point.

My point is that one will not be given the opportunity to open a 10-12 HCP 1NT opening as often as one will be given the opportunity to open a 15-17 HCP 1NT opening due to:

(1) An opening bid by an opponent prior to the first opportunity to bid for the balanced 10-12 HCP hand.

(2) An opening bid by partner prior to the first opportunity to bid for the balanced 10-12 HCP hand.

(3) System restrictions which prohibit opening a 10-12 HCP 1NT in third or fourth seat.

(4) System restrictions which prohibit opening a 10-12 HCP 1NT vulnerable.

It is also possible that points #1 and #2 apply to a 15-17 HCP 1NT opening, but, given that there are fewer HCPs available for the other three hands when one holds a balanced 15-17 HCP hand, the possibility of a prior opening bid is diminished.

As to point #3, I play a 10-12 HCP 1NT opening nonvulnerable in 1st and 2nd seat in the context of a light opening system (all 10 counts are opened). Partner's pass in 1st or 2nd seat would deny 10 HCP, so it would be suicidal to open a 10-12 HCP 1NT in 3rd of 4th seat. Consequently, we play 15-17 HCP 1NT openings in 3rd or 4th seat (and all seats vulnerable). I have made an argument to my partner that our 3rd and 4th seat 1NT openings should be 16-18 HCP, but he has not accepted my argument.

Given all of my restrictions, I find that a 10-12 HCP 1NT opening is LESS frequent than a 15-17 HCP 1NT opening.

[hrothgar]

ArtK78, on Jul 17 2009, 03:20 PM, said:

The simulation shows what we all knew to be the case: Balanced hands with 10-12 HCP are far more common than balanced hands with 15-17 HCP.

That is not the point.

My point is that one will not be given the opportunity to open a 10-12 HCP 1NT opening as often as one will be given the opportunity to open a 15-17 HCP 1NT opening due to:

(1) An opening bid by an opponent prior to the first opportunity to bid for the balanced 10-12 HCP hand.

(2) An opening bid by partner prior to the first opportunity to bid for the balanced 10-12 HCP hand.

(3) System restrictions which prohibit opening a 10-12 HCP 1NT in third or fourth seat.

(4) System restrictions which prohibit opening a 10-12 HCP 1NT vulnerable.

It is also possible that points #1 and #2 apply to a 15-17 HCP 1NT opening, but, given that there are fewer HCPs available for the other three hands when one holds a balanced 15-17 HCP hand, the possibility of a prior opening bid is diminished.

As to point #3, I play a 10-12 HCP 1NT opening nonvulnerable in 1st and 2nd seat in the context of a light opening system (all 10 counts are opened). Partner's pass in 1st or 2nd seat would deny 10 HCP, so it would be suicidal to open a 10-12 HCP 1NT in 3rd of 4th seat. Consequently, we play 15-17 HCP 1NT openings in 3rd or 4th seat (and all seats vulnerable). I have made an argument to my partner that our 3rd and 4th seat 1NT openings should be 16-18 HCP, but he has not accepted my argument.

Given all of my restrictions, I find that a 10-12 HCP 1NT opening is LESS frequent than a 15-17 HCP 1NT opening.

Please go back and review how the simulation was constructed.

Wayne's simulation didn't assume the use of a 10-12 HCP 1NT opening. (It used a slightly more conservative opening style). However, I doubt that this would change the results that much.

Indeed, I'd bet dollars to donuts that a system using a 15 - 17 HCP 1NT opening in all four seats will have (significantly) fewer 1NT opening than one that uses a 10-12 HCP 1NT opening in all four seats. Your claim Cthat people shouldn't open a 10-12 NT in 4th seat therefore these frequencies shouldn't be excluded seems like apples to oranges comparison.

For what its worth, I agree that a system that uses a 10-12 HCP 1NT opening in all four seats will open 1NT less frequently than one that opens

10-12 in first / second
11-13 in third
14 - 16 in fourth

Let's go back to the original discussion:

If you prefer, we can modify my original argument as follows:

Rather than looking at a system than uses a 10-12 HCP 1NT opening in all four seats, lets look at a system designed to maximize the frequency of a 1NT opening all four seats.

Contrast the freqency of said NT opening with that of a 15 -17 HCP 1NT opening...

[ArtK78]

My primary point is that someone else is likely to open in front of a 10-12 1NT opener more often than someone else is likely to open in front of a 15-17 1NT opener, limiting the opportunity to open a 10-12 1NT.

[rbforster]

ArtK78, on Jul 17 2009, 07:20 AM, said:

As to point #3, I play a 10-12 HCP 1NT opening nonvulnerable in 1st and 2nd seat in the context of a light opening system (all 10 counts are opened).  Partner's pass in 1st or 2nd seat would deny 10 HCP, so it would be suicidal to open a 10-12 HCP 1NT in 3rd [or 4th] seat. 

I'm not dead yet!

I play a very similar opening style, but we open a 10-12 NT in 3rd seat (although not 4th for constructive reasons). Admittedly this is only when we're NV, but it's not an obviously bad thing.

[hrothgar]

ArtK78, on Jul 17 2009, 04:41 PM, said:

My primary point is that someone else is likely to open in front of a 10-12 1NT opener more often than someone else is likely to open in front of a 15-17 1NT opener, limiting the opportunity to open a 10-12 1NT.

Wayne, any chance you could rerun the simulation to address this?

[ArtK78]

Rob F, on Jul 17 2009, 08:42 AM, said:

ArtK78, on Jul 17 2009, 07:20 AM, said:

As to point #3, I play a 10-12 HCP 1NT opening nonvulnerable in 1st and 2nd seat in the context of a light opening system (all 10 counts are opened).  Partner's pass in 1st or 2nd seat would deny 10 HCP, so it would be suicidal to open a 10-12 HCP 1NT in 3rd [or 4th] seat. 

I'm not dead yet!

I play a very similar opening style, but we open a 10-12 NT in 3rd seat (although not 4th for constructive reasons). Admittedly this is only when we're NV, but it's not an obviously bad thing.

With all due respect, if you are playing against opponents who are not brain-dead, and you open a 10-12 1NT opposite a partner who has denied as many as 10 HCP, they should double you without even looking at their hands.

[rbforster]

ArtK78, on Jul 17 2009, 09:01 AM, said:

if ... you open a 10-12 1NT opposite a partner who has denied as many as 10 HCP, they should double you without even looking at their hands.

Little do they know I've got 3 places to play since I'm 4441!

[aguahombre]

Rob F, on Jul 17 2009, 11:50 AM, said:

ArtK78, on Jul 17 2009, 09:01 AM, said:

if ... you open a 10-12 1NT opposite a partner who has denied as many as 10 HCP, they should double you without even looking at their hands.

Little do they know I've got 3 places to play since I'm 4441!

deserving of more than one smiley face....great irony.

[ArtK78]

Rob F, on Jul 17 2009, 11:50 AM, said:

ArtK78, on Jul 17 2009, 09:01 AM, said:

if ... you open a 10-12 1NT opposite a partner who has denied as many as 10 HCP, they should double you without even looking at their hands.

Little do they know I've got 3 places to play since I'm 4441!

One man's version of Hell:

You are 4441 for your 10-12 1NT opening opposite a passed partner. LHO doubles, Partner runs to his 5 card suit (opposite your singleton).

Not only do you go for a number, but you get a procedural penalty when it becomes apparent that you often open your 10-12 1NT openings with a singleton.

OR

Partner does not run to his 5 card suit (which is not opposite your singleton) BECAUSE you frequently open 1NT with a singleton. Again, you go for a number, and again you get a procedural penalty.

[aguahombre]

all true, art....but certainly Rob knew all this when he made his joke--no doubt from experience if he plays that range.

[Cascade]

hrothgar, on Jul 18 2009, 01:51 AM, said:

ArtK78, on Jul 17 2009, 04:41 PM, said:

My primary point is that someone else is likely to open in front of a 10-12 1NT opener more often than someone else is likely to open in front of a 15-17 1NT opener, limiting the opportunity to open a 10-12 1NT.

Wayne, any chance you could rerun the simulation to address this?

Honestly I don't understand his point.

The simulation already takes into account the possibility of someone opening in front of the second, third and fourth seat openings.

A pair playing 10-12 will have someone (partner) opening slightly more often since partner might open 1NT in first or 2nd seat. Is this the simulation you would like for me to do?

[TimG]

Cascade, on Jul 17 2009, 02:29 PM, said:

hrothgar, on Jul 18 2009, 01:51 AM, said:

ArtK78, on Jul 17 2009, 04:41 PM, said:

My primary point is that someone else is likely to open in front of a 10-12 1NT opener more often than someone else is likely to open in front of a 15-17 1NT opener, limiting the opportunity to open a 10-12 1NT.

Wayne, any chance you could rerun the simulation to address this?

Honestly I don't understand his point.

The simulation already takes into account the possibility of someone opening in front of the second, third and fourth seat openings.

A pair playing 10-12 will have someone (partner) opening slightly more often since partner might open 1NT in first or 2nd seat. Is this the simulation you would like for me to do?

Sitting in 2nd seat with 10-12, sometimes RHO will open in front of you taking away your chance to open 1N.

Sitting in 2nd, 3rd or 4th seat with 15-17, sometimes someone will open in front of you taking away your chance to open 1N.

I thought you already took that into account, but Richard and Art don't seem sure.

[Cascade]

I thought I did too.

[hrothgar]

Cascade, on Jul 17 2009, 11:02 PM, said:

I thought I did too.

I wasn't sure whether your simulation included both the change in the conditional probability and the effect on the frequency of a first/2nd/whatever seat opening...

[Cascade]

hrothgar, on Jul 18 2009, 08:09 AM, said:

Cascade, on Jul 17 2009, 11:02 PM, said:

I thought I did too.

I wasn't sure whether your simulation included both the change in the conditional probability and the effect on the frequency of a first/2nd/whatever seat opening...

1st column - frequencies for 100 000 000 hands

2nd column - frequencies for 100 000 000 hands constraining 1st seat to have a PASS by the rules I outlined

etc