[ncohen]

10874 QJ2
104 Kq73
K32 A1084
K976 Q3

MP lead: club 5.

auction
N E S W
P 1D 1H x
P 1N (all pass)

On this hand, I was proud of using reasoning about GIB's defense to overcome my lack of concentration.

N won the club A and returned a heart -- low J low. Then, ht A and another club. I attacked spades. At a critical part of the hand, after S took his 2nd spade trick (with me not noticing the fall of the S9 from N), he exited with the S5. I won the 10 in W this position:

8
-- Kq
K32 A108x
K9 ---

I hadn't notice the fall of the 9, but figured that GIB probably wouldn't have returned a spade to make a finesse easy. Also, there was nothing to lose by playing the S 8, since the other suits were under control. So, I played it, discarding a diamond, and it captured W's 6 for an overtrick.

[smerriman]

I can't quite follow the story. If you lead the Q of spades at trick 5, lose the K and A of spades and get a spade exit by South, you still have the jack and ten left to win the next two tricks.

[ahydra]

Please use the hand diagram tool (spade icon on right of editor toolbar).

GiB doesn't take into account human-type inferences like this - it uses double-dummy simulations and as such will often do silly things because it "knows" that the declarer will always get a guess right.

ahydra

[ncohen]

ahydra, on 2019-January-21, 22:26, said:

GiB doesn't take into account human-type inferences like this - it uses double-dummy simulations and as such will often do silly things because it "knows" that the declarer will always get a guess right.

ahydra

Good point! But, if there's a chance GIB doesn't know I have a 3rd spade, then the spade return can give up a trick, since I'd be unable to finesse. So, there's a slight inference that the S 8 is good.

[zenbiddist]

It takes extra mental effort to try and work out what's going on without a diagram, so I made one for you:

---

I'm still trying to piece together what happened.

Trick 1: Club to North's ace
2: Heart ducked to South's jack
3: ♥A
4: Club won in East
5: Declarer knocks out a top spade
6: Sounds like North won and exited the ♠9, and you played high from Hx in your hand? Or South cashed two top spades, and you unblocked?
7: South exits a third round of spades, dummy's ♠T winning

Perhaps you could find the hand for us here, and post the handviewer link: https://www.bridgeba...p?&from_login=1

[GrahamJson]

Hmm. If you fail to notice the fall of the nine of spades, which is after all a critical card, I’m not sure that you can call any subsequent reasoning “expert”.