How did GIB play it?

[Wackojack]

[hv=d=e&v=n&w=sq1092hq2dakq96c86&e=sa7hk963d4cakqj92]266|100|Scoring: IMP

E S W N

1♣ p 1♦ 1♥

3♣ p 3♠ p

3nt p 6nt p p

p [/hv]

 

Human South led ♥10 covered by Q, Ace, 3. GIB North returned the ♥8. GIB East spurned the marked!! finesse taking with the King, South following with the 5. GIB proceeded to make the contract. Any guesses how and why? Would you play it this way?

[hotShot]

GIB does not know much about leading agreements, but is great in counting.

 

So lets count:

West has 2♥'s, East has 4♥'s this means 7♥ are with NS.

North bid 1♥ showing 5+ of these. After the first trick, North has 4+♥'s and south is left with 1-♥'s. So the chance that the J is with north is 80%.

So GIB is 80% confident that north has the ♥J and is taking the finesse.

 

So if playing ♥10 is not promising the J this seems to be the best plan, even for humans.

[jtfanclub]

At a guess? It's marked North with the spade king, and can therefore squeeze the hand out.

 

After taking the 2nd heart, run off 6 clubs, dicarding two diamonds and two spades.

 

[hv=w=sqthdakqc&e=sa7h93d4c]266|100|[/hv]

 

On the second diamond, discard a heart. On the last diamond, North has to reduce himself to two cards...either the Kx of spades or the K of spades and J of hearts. Either way, EW makes the contract.

 

So once it decides that North has the spade king, finessing the heart is unnecessary.

[hotShot]

You may be right, but GIB is always guessing.

GIB samples a few hands (I think it can do 5-10 in the given time) and checks what move is best.

Asuming that north holding is 5+ ♥'s, it is possible that GIB sampled a hand or two where the ♠K is with south. Making the finesse look better.

 

The relevance of the sampled hands, get's better the more cards have been played. At trick 2 GIB's analyzed sample set may be quite far from the true distribution.

[foo]

jtfanclub got it.

[Fluffy]

I'd say he cashed ♠A at viena coup and tried for the 'double' squeeze, or diamond drop.

[Wackojack]

Yes jtfan got it exactly. Why would GIB make such a play? It strikes me that GIB gave itself the extra chance that human south was leading from J10 doubleton. When that proved not to be the case then the squeeze on North would operate, provided that North also held the King of spades. Probably not a good enough reason for a human to do this.

 

Interesting that had GIB played Vienna coup according to Fluffy's guess it would also have succeeded as North held 10xxx in diamonds and so would be squeezed in 3 suits.