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How to induce a step-up

#1 User is offline   helene_t 

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Posted 2016-April-19, 06:33

Yesterday I had this suit combo:

N(dummy): K8752
S(decl): T964

Instinctively I played the T from the hand to induce a cover, but afterwards I realized that it doesn't matter if W covers with Q3, J3 or QJ3. (OK, if I had decided for some reason to play to the king then I would like to induce a cover from QJ3).

What I need is to induce W to step up from A3, AQ3 or AJ3. I suppose I achieve this by pretending to be stealing a trick, but I wonder if that means that I should lead a low card. Maybe playing a low card looks like I plan to play to the king and then finesse against East, in which case it obviously won't induce a step-up. Maybe it doesn't matter or maybe this is an infinite loop of reverse psychology. But maybe I am missing something?
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#2 User is offline   robert2734 

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Posted 2016-April-19, 14:41

If you play to the king, you have one loser when W has AQ, AJ, or A3. If you run the ten, you never have one loser. If you run the ten and W has QJ3, you have two losers instead of three so maybe it has merit as a safety play.

Are you in trump and is this suit trump? W with AQ3 hopes you are playing to the king and he'll get two tricks so he'll never step up. W with AJ3 hopes you have QT94 and are playing to the king so he'll never step up. W with A3 hopes partner has Q4 and you misguess so he'll never step up.
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#3 User is offline   Tramticket 

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Posted 2016-April-20, 05:26

How many tricks are you playing for Helene? If you are playing for four tricks, then I think you need to hope for a 2-2 split with the ace with West (about 26% -EDIT 20%) and lead towards the king on the first round.

As you note there is an additional chance if West holds AQ3 or AJ3 and rises with the ace dropping East's honour. You can then finesse against West on the second round. But if West holds A3 opposite QJ in East you will lose two tricks by taking the second round finesse. The principle of restricted choice might suggest taking the second round finesse on the basis that West holding AQ3/AJ3 is more likely than West holding A3. BUT West has no reason to rise with the Ace with AQ3/AJ3, whereas it might be a clever bluff to rise with the Ace with A3.

It might depend on (a) your opinion of the abilities of the opponents and (b) the rest of the hand (is there a reason for West to rise with the Ace, because he wants to switch?).
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#4 User is offline   Zelandakh 

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Posted 2016-April-20, 08:15

I did this quickly so there are probably mistakes but a (loser) trick table is:

----- K T
AH/H3 1 1
A3/QJ 1 2
QJ/A3 2 2
H3/AH 2 2
AQJ/3 2 2
AH3/H 2 3
QJ3/A 3 2
A/QJ3 2 2
H/AH3 2 2
3/AQJ 3 3
AQJ3/- 3 2
-/AQJ3 3 3

The king looks to be easily better for maximum expectation and 1 loser. Even for 2 losers, the AH3/H case is dominant so the king looks to be better here too. of course if you think West will pop an honour from that AH3 combination it is another thing altogether but in that case you are probably beating the opposing pair easily enough over a few boards.
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#5 User is offline   helene_t 

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Posted 2016-April-20, 08:59

Zel: for AH3/H it is 2-2
I believe that for expected tricks or two losers it is best to cover an honour but play low over low. For one loser, if w plays low the only chance is ax-qj so you play the king. The scenario where W plays ace droping easts honour is not so clear. RS suggests finessing but maybe psychology suggests playing for ax-qj
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#6 User is offline   Phil 

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Posted 2016-April-20, 12:05

If the defense knows we have five, they should never cover from QJX unless declarer has some crazy read on our hand.

If four is possible then covering loops clear.

Again, matters like if it's mps or how many tricks seem to matter.
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#7 User is offline   helene_t 

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Posted 2016-April-21, 04:40

On the actual hand I needed four tricks to make although you never know what your target is when you play matchpoints in a small, weak field. There is also the issue that if you are short of entries to your hand, playing low to the king gives you two tricks when E has a singleton honour. But to be honest I am not sure how my thought process was at the table, I think I just had a vague feeling that playing the king was right. The suit turned out to split Ax-QJ.
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#8 User is offline   TylerE 

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Posted 2016-April-22, 11:27

Suitplay says the best line (by about 5%) is lead to the K
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