[lamford]

---

This was an interesting hand from the EBU SIMs last night. Tables reached 4H by South and usually West led three rounds of clubs. South ruffed, cashed the ace of spades, ten, small, three, and drew trumps in two rounds ending in dummy. Now a spade from dummy produces the seven from East. It would seem that ducking is twice as likely to succeed as rising. Do readers concur?

[DavidKok]

Yes. If West has the 3-card suit you're never making, and the opening denies a singleton ten. So West must have started with either exactly KT or JT, and restricted choice applies.

[Cyberyeti]

DavidKok, on 2022-September-07, 05:44, said:

Yes. If West has the 3-card suit you're never making, and the opening denies a singleton ten. So West must have started with either exactly KT or JT, and restricted choice applies.

Except W opened 1N, if he has ♠J, ♣KQ, nothing in hearts, he has ♦AK and might well have led one unless he only had 11, so he probably has the ♠K, I admit with the intermediates he has, he could well have opened with 11 but you don't get to see those first)

[DavidKok]

There's no 'except', I did see West opened. I'm saying that in the case West has 3 spades they must be exactly KJT and we are always losing two spades along with two clubs (since East has shown us the 3 and 7 - which also rules out West having 4 or more). Conversely, the spades can not split 1-4 (East holding 4) unless West opened 1NT with a singleton ♠T, which I also rule out. I think many players playing 12-14 NT would consider opening 1NT with ♠JT, ♥T2, ♦AJT85, ♣KQT9 (look at those tens!), but it is a good point that the odds favour ducking even more than the classical 2:1 restricted choice argument.

Or did you mean that ducking is a favourite, but you want to explain that the odds are better than 2:1? I agree, but the lines are identical.

[Cyberyeti]

DavidKok, on 2022-September-07, 07:35, said:

There's no 'except', I did see West opened. I'm saying that in the case West has 3 spades they must be exactly KJT and we are always losing two spades along with two clubs (since East has shown us the 3 and 7 - which also rules out West having 4 or more). Conversely, the spades can not split 1-4 (East holding 4) unless West opened 1NT with a singleton ♠T, which I also rule out. I think many players playing 12-14 NT would consider opening 1NT with ♠JT, ♥T2, ♦AJT85, ♣KQT9 (look at those tens!), but it is a good point that the odds favour ducking even more than the classical 2:1 restricted choice argument.

Or did you mean that ducking is a favourite, but you want to explain that the odds are better than 2:1? I agree, but the lines are identical.

I think restricted choice doesn't fully apply.

You don't know they have all those intermediates, if they have AJ and 3 very small diamonds or lack the J, it seems less likely they would upgrade, so that makes the ♠K more likely, certain the approximately 50% of the time they don't have the J♦ or indeed have the K but not the A.

[Gilithin]

Can we not make a discovery play in diamonds first by leading the queen instead of a second spade? Once we find out that East has ♣A and ♦K, it is a guarantee that West has ♠K even beyond the inferences of the lead and auction. Even if East ducks in tempo, we do not appear to be any worse off than the immediate spade.

[DavidKok]

Cyberyeti, on 2022-September-07, 08:04, said:

I think restricted choice doesn't fully apply.

You don't know they have all those intermediates, if they have AJ and 3 very small diamonds or lack the J, it seems less likely they would upgrade, so that makes the ♠K more likely, certain the approximately 50% of the time they don't have the J♦ or indeed have the K but not the A.

You're missing the point. If West has the king, we have to duck. All these inferences about West's point count make ducking an even bigger favourite, compared to the 'raw' 2:1 odds from restricted choice. I'm not sure why you would describe that as "doesn't fully apply".

[Cyberyeti]

DavidKok, on 2022-September-07, 10:00, said:

You're missing the point. If West has the king, we have to duck. All these inferences about West's point count make ducking an even bigger favourite, compared to the 'raw' 2:1 odds from restricted choice. I'm not sure why you would describe that as "doesn't fully apply".

I was saying restricted choice was irrelevant here the odds were massively in favour of the K being with W even without it, basically of all the hands where W has K10 or J10, there is pretty much only one J10, xx, AJ10xx, KQ10x where he has J10, so the odds are way more than the 2:1 from restricted choice.

[michel444]

lamford, on 2022-September-07, 05:23, said:

---

This was an interesting hand from the EBU SIMs last night. Tables reached 4H by South and usually West led three rounds of clubs. South ruffed, cashed the ace of spades, ten, small, three, and drew trumps in two rounds ending in dummy. Now a spade from dummy produces the seven from East. It would seem that ducking is twice as likely to succeed as rising. Do readers concur?

I still asking myself why open 1 NT ?
seem like a no 4 cards major NT of some kind of Major always first
so it can be even a 1=3=4=5 distribution