[DavidKok]

The hand remains a clear takeout double when partner is limited to 10 points, in my opinion. You can't afford to be deterred by a singleton king in their suit. It's a bidder's game! Of course this is subject to partnership understanding, as is everything else, but I think a partnership understanding that insists on pass with this hand will lose out in the long run. I've lost my fear of -800 or even -1100 years ago, it just doesn't happen that often.

[AL78]

 pescetom, on 2022-February-14, 14:22, said:

I was referring to the statistical probability of fit, but of course you are right in terms of actually finding a fit. Many with 4 hearts and 5 clubs would bid hearts after double, come to that. There is however also the issue that 2♣ is not very preemptive and if made on 5=cards then a raise requires 4+card fit to be protected by LoTT. There is also vulnerability, not specified here.

I may be behind the times in terms of aggressive bidding, but there is no way I am overcalling 2♣ on KJxxx.

[pescetom]

 bluenikki, on 2022-February-14, 07:11, said:

I no longer have the notes from my calculations, but:

Suppose you have 5431 shape with shortness in opener's suit. Suppose also that an angel has whispered in your ear that your side has an 8-card fit.

Then the chance that is in your 5-card suit is significantly lower than the combined chances that it is in your 3- or 4-card.

I gave in to curiosity and simulated to find fits with the hand in OP.

If the angel meant that your side has at least one fit of exactly 8 cards, then the chance of clubs is 32.1% and the chance of the red suits combined is 32.8%, so almost the same.

If the angel meant that your side has at least one fit of at least 8 cards, then the chance of clubs is 61.6% and the chance of the red suits combined is 64.9%, so clubs a bit lower.

But if the angel meant that your side has exactly one fit of exactly 8 cards (and no longer fit in another suit), then the chance of clubs is 47% and the chance of the red suits combined is 53%, so clubs significantly lower (see second printout).

So I guess it's all down to semantics, even for angels.

____________________________________________________________________________


Frequency of length of fit in each suit, irrespective of fit in the others:

Quote

Frequency of C fit:
Low 384018
8 319199
9 208878
10 73135
11 13510
12 1224
13 36
Frequency of D fit:
Low 603653
8 250172
9 113654
10 28503
11 3780
12 230
13 8
Frequency of H fit:
Low 747533
8 176401
9 62286
10 12424
11 1297
12 59
13 0
Generated 8964278 hands
Produced 1000000 hands
Initial random seed 1644939662
Time needed 8.167 sec

Relative frequency of fit suit when there is exactly one 8 card fit and no longer fit:

Quote

Frequency only C 8fit:
0 159652
1 148028
Frequency only D 8fit:
0 214614
1 93066
Frequency only H 8fit:
0 241094
1 66586
Generated 10000000 hands
Produced 307680 hands
Initial random seed 1644941882
Time needed 9.002 sec

[bluenikki]

 pescetom, on 2022-February-15, 10:38, said:

I gave in to curiosity and simulated to find fits with the hand in OP.

If the angel meant that your side has at least one fit of exactly 8 cards, then the chance of clubs is 32.1% and the chance of the red suits combined is 32.8%, so almost the same.

If the angel meant that your side has at least one fit of at least 8 cards, then the chance of clubs is 61.6% and the chance of the red suits combined is 64.9%, so clubs a bit lower.

But if the angel meant that your side has exactly one fit of exactly 8 cards (and no longer fit in another suit), then the chance of clubs is 47% and the chance of the red suits combined is 53%, so clubs significantly lower (see second printout).

So I guess it's all down to semantics, even for angels.

____________________________________________________________________________


Frequency of length of fit in each suit, irrespective of fit in the others:



Relative frequency of fit suit when there is exactly one 8 card fit and no longer fit:

Probably it doesn't matter, but I did not do a simulation. Instead, I produced a long ugly speardsheet full of binomial coefficients.

Best I can recall, the results were not as close as these simulations.

Carl

[Lovera]

The difference between the modern bid for this type of competing hands lies in bidding first a suit and then doubling when the points are well distributed in the other suits (when these are not well represented it is immediately doubled) while in the classic one the double is preferred for show points then declaring a suit. However, in both cases there is no disregard for having a Major suit fourth which is missing here and it is for this reason that 2 ♣ must be chosen ( which implicitly indicates points). The bid of Double has complications but due to its importance it is not advisable to resort to simplifications or excessive generality.