[sakuragi]

1. challenge match against friend
bidding and opening lead
how do u weigh your chance? >50%?
would u active go on clubs or passive unblock and exit?
Seems like C33, C42 with CT falling, and opps could win 5 quick tricks I opt for clubs ....

2. after unblock Diamond and Clubs, u have not seen C10 falling from West
at this point
would you overtake your club?
Has your odds changed vs after opening lead?

3. I overtook CJ and Doomed ... down 1
Your friend +1 and the card play is
same opening D lead
cash CAJ
cash Dq
small H and West play HK
Are u unlucky or a well deserved loss?

[Stephen Tu]

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I don't like either line. You banked it all on clubs behaving. A shade above 50. Your challenger banked it all on hearts onside, essentially. Worse.

I think what is actually best is to win the diamond and lead a heart up immediately. It's rather unlikely that they can get 4 spade tricks off the top; the suit is blocked more often than not, and even when it isn't they aren't always going to find the low shift from HHHx or the high one from Hx.

Then if the heart doesn't work you can fall back on clubs behaving if they haven't cashed 4 spade tricks on you. If hearts work you unblock clubs and take 2 hearts and 2 diamonds only or 3 diamonds and 1 heart only depending on which entries they attack.

[johnu]

The problem with unblocking, is that you are only 50% to get to dummy with a heart. And even if you can guess hearts (or West has ♥KJ, it should be easy for the opponents to cash 4 spades if spades are not 3-3 or blocked so that's 5 losers.

Unblocking diamond and overtaking ♣J wins when clubs are 3-3 or 4-2 with doubleton 10. That's 36% + 1/3 x 48% so you are ~52%.

[cherdano]

The bots usually go up with the king if you play a heart up, so it's closer to 75% than to 50% that you have a heart entry.

[johnu]

cherdano, on 2018-November-11, 02:33, said:

The bots usually go up with the king if you play a heart up, so it's closer to 75% than to 50% that you have a heart entry.

You could be right but very small differences in cards and carding can lead to dramatically different GIB actions. I don't have enough data points to make a better guess.

[smerriman]

cherdano, on 2018-November-11, 02:33, said:

The bots usually go up with the king if you play a heart up, so it's closer to 75% than to 50% that you have a heart entry.

In a sense that makes playing a heart a worse option though, since your best hope is that West has the king and doesn't play it.

If West jumps up with the king, there's about a 56% chance of a 3-3 or blocked spade suit. But in the other cases, remembering South is dummy, I don't think the right spade switch will be too hard to find. And given the other 50% of the time East will win the King and you haven't gained anything, the heart seems too risky.

[cherdano]

smerriman, on 2018-November-11, 18:29, said:

In a sense that makes playing a heart a worse option though, since your best hope is that West has the king and doesn't play it.

If West jumps up with the king, there's about a 56% chance of a 3-3 or blocked spade suit. But in the other cases, remembering South is dummy, I don't think the right spade switch will be too hard to find. And given the other 50% of the time East will win the King and you haven't gained anything, the heart seems too risky.

I think it will be quite rare that the bots find the low spade switch from HHHx, and not that often the switch from Hx. They don't know that there are five club tricks (if you play the heart at trick two as suggested by Stephen). They are not getting a suit preference signal from partner. And remember that the low switch from HHHx is ONLY necessary when declarer has precisely xx - it's wrong when he has a singleton honour or Hx, and not necessary when he has x. And the a priori odds are s.th. like 16:6 for declarer to have Hx instead of xx in spades. Switching to Jx through declarer's Qx or Kx or even Ax would be a disaster on so many layouts. And even if they do switch to a low spade from HHHx, it's not clear that their partner bot will continue the suit.

[cherdano]

By the way, the third question is the wrong question to ask. It's not about "did I deserve to win" but "could I have done s.th. better to improve my chances of winning".

[Stephen Tu]

Quote

If West jumps up with the king, there's about a 56% chance of a 3-3 or blocked spade suit

How are you getting only 56%? I am looking at much higher figure, especially if you think person on lead with AKQJ(...) is likely to have opened and/or led the suit. Close to 70% at least.

[smerriman]

Was just considering the suit in isolation (3-3 + 6/15 * 4-2 + 4/6 * 5-1). But yeah, I didn't consider the lead.

[msjennifer]

Sir I too opted for your line.However my partner asked me one question ."Why not play on spades ?"
"

[nige1]

My guess:
Cash ♦KQ ♣AJ
Overtake if LHO plays ♣T or (trustworthy human) defenders signal odd-length.
Otherwise exit in ♠ and hope for the best

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