[shyams]

This came up at MPs against bots. I reviewed the bidding & the opening lead at all other tables, it was identical to what occurred at mine.

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West led ♦J - ♦3 - ♦2 -♦A. Plan the play.

Additional info: If you later play a diamond from dummy, East will play the ♦6 and West the ♦4. As these are bots defending, I think there is not much to be inferred from the carding (i.e. West's diamond suit could be any of ♦JT96, ♦JT6 or ♦J6; it is unlikely to be ♦J96)

[AL78]

My plan would be to discard one spade on dummy's diamond winners. I play a heart to dummy and play a top diamond, throwing a spade, then run the ♣T. Win the return (unless East holds ♣KQ and covers then I can knock out the second honor for two club tricks). If they try to cash three rounds of spades, ruff then go for the club ruff and claim. If they knock out dummy's last heart, take the club finesse. I fail if West holds both club honors, but it might have led the ♣K in that case. This gives up on an overtrick if the diamonds are 3-3, but avoids going down if the diamonds are not 3-3, but I try to cash both of dummy's diamond honors. I don't think any of my regular partners would criticise me for that line if I go down. If the diamonds are 5-1 and it requires the brain of a world champion to find the solution in a suitable time which also works on all the more likely diamond breaks, I'll apologise for not being talented enough to find it.

[FelicityR]

Play for the odds, which I guess - too hot to work them out today, phew 93F! - that ♦s are more likely to be 4-2 than 3-3, and the ♣ honours are split (or East has ♣KQ). I agree with AL78 that is the way to play the hand. What players forget at match points is that making the contract is just as important as overtricks. There's a needy way to play this board where you need a top desperately, and a considered way of playing.

[AL78]

 FelicityR, on 2020-August-10, 12:07, said:

Play for the odds, which I guess - too hot to work them out today, phew 93F!

Yes it sucks, SE England is going through a heatwave and it has been 30+C (86+F) for several days, and will be for the next 2-3 days, with overnight minimums not dropping below 20C (68F). No air conditioning, so no escape from it.

[bluenikki]

 AL78, on 2020-August-10, 12:14, said:

Yes it sucks, SE England is going through a heatwave and it has been 30+C (86+F) for several days, and will be for the next 2-3 days, with overnight minimums not dropping below 20C (68F). No air conditioning, so no escape from it.

Famous apocryphal London headline: "72 again today. No relief in sight."

[shyams]

 AL78, on 2020-August-09, 07:04, said:

My plan would be to discard one spade on dummy's diamond winners. I play a heart to dummy and play a top diamond, throwing a spade, then run the ♣T. Win the return (unless East holds ♣KQ and covers then I can knock out the second honor for two club tricks). If they try to cash three rounds of spades, ruff then go for the club ruff and claim. If they knock out dummy's last heart, take the club finesse. I fail if West holds both club honors, but it might have led the ♣K in that case. This gives up on an overtrick if the diamonds are 3-3, but avoids going down if the diamonds are not 3-3, but I try to cash both of dummy's diamond honors.

The above line is obviously very good at IMPs; it improves the odds of bringing in 10 tricks.

My issue was that it was MPs. Can I (or should I) play for a different layout where the upside of scoring +1 is higher than the downside of being defeated in a "cold" game? For example, is ♦A followed by both trumps in dummy, then top ♦ better given that an additional chance of ♦ 4-2 but the doubleton holder also has ♥xx and is unable to ruff?

[miamijd]

 shyams, on 2020-August-10, 20:04, said:

The above line is obviously very good at IMPs; it improves the odds of bringing in 10 tricks.

My issue was that it was MPs. Can I (or should I) play for a different layout where the upside of scoring +1 is higher than the downside of being defeated in a "cold" game? For example, is ♦A followed by both trumps in dummy, then top ♦ better given that an additional chance of ♦ 4-2 but the doubleton holder also has ♥xx and is unable to ruff?

Al's line is better, and it's pretty easy to analyze. When do the lines differ in their results?

1. If the third diamond is ruffed, then Al's line is better unless West has both club honors (in which case both lines go -1).

2. If the third diamond honor lives, your line is better only if West has both club honors.

In #2, the lines are equal if the club honors are split, because Al gets to take two C hooks, but you only get one (so you lose two C tricks and a spade; Al loses one C trick and 2 spades). Likewise, the lines are equal if East has both C honors, because Al will get a second chance to throw a spade on the third diamond (he wins when East splits his C honors, goes back with a trump, and plays a D honor since he doesn't need the second C hook any more).

Considering just the diamonds, I think case 2 is ever so slightly more likely than case 1. BUT - case 2 only wins if West has both club honors, whereas case 1 wins UNLESS West has both club honors.

West is not at all likely to have both club honors, because on the bidding, a lead from KQ(xxx) is a lot more attractive than one from 2-4 of dummy's suit.

Thus, 1 will gain almost all the time when the third diamond is ruffed. 2 generally won't gain vs. 1 even if the third diamond lives.

Go with Al's line -- #1.

Cheers,
Mike

[Vampyr]

 AL78, on 2020-August-10, 12:14, said:

Yes it sucks, SE England is going through a heatwave and it has been 30+C (86+F) for several days, and will be for the next 2-3 days, with overnight minimums not dropping below 20C (68F). No air conditioning, so no escape from it.

Friday it was 99. Since then (possibly since Wed or Thurs even) the Mercury has not failed to hit 90. Global warming is a bitch.

Was it Gordon Brown who predicted it would be a “barbecue summer” while he was Prime Minister? That year it was a normal English summer, cold and rainy nearly every day. We didn’t know how good we had it!

I think I have to shop in Sainsbury’s for a few hours. I might even buy something.

[AL78]

 bluenikki, on 2020-August-10, 19:53, said:

Famous apocryphal London headline: "72 again today. No relief in sight."

72F would be about average, that has been the dew point over the last week. Try 100F then 99F the following week. Temperatures that high are extreme for the UK. Trying to get to sleep when it is over 80F in your bedroom at midnight is not fun.

[AL78]

 Vampyr, on 2020-August-11, 05:39, said:

Was it Gordon Brown who predicted it would be a “barbecue summer” while he was Prime Minister? That year it was a normal English summer, cold and rainy nearly every day. We didn’t know how good we had it!

There was a year when the UK Met Office were issuing seasonal forecasts and predicted a greater probability than normal of a warmer than average summer. The media jumped on this and massively blew it out of proportion with headlines like "100F this summer", "Barbeque summer". Unfortunately the media (and most of the public) don't understand probabilistic forecasts, and the media are interested in sensationalism, not the truth.

Anyway, this is OT for a bridge forum, sorry.

[nige1]

shyams 'This came up at MPs against bots. I reviewed the bidding & the opening lead at all other tables, it was identical to what occurred at mine.West led ♦J - ♦3 - ♦2 -♦A. Plan the play. Additional info: If you later play a diamond from dummy, East will play the ♦6 and West the ♦4. As these are bots defending, I think there is not much to be inferred from the carding (i.e. West's diamond suit could be any of ♦JT96, ♦JT6 or ♦J6; it is unlikely to be ♦J96).
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
My greedy guess. ♦A ♥ ♦s.
- If both opponents follow to 3 rounds discard 2 ♠s and take the ♣ finesse.
- If a defender ruffs the 3rd ♦, then over-ruff if possible. Anyway cross to dummy's ♥Q, and finesse ♣s, hoping RHO has ♣KQ.

Arithmetic is not my long suit but
- Two rounds of ♦ then 2 ♣ finesses = (48% + 36%) X 75% = 63%
- Three rounds of ♦ then a ♣ finesse = 36% + (48% X 25%) = 48%
- But 36% of the time you have a 75% of an overtrick = 27%
If most players reach game that might swing the the odds in favour of the greedy line.

Oh dear, I overlooked the fact that if both clubs are right, then a declarer, who takes 1 diamond discard and finesses clubs, also makes an overtrick when diamonds are 3-3

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This post has been edited by nige1: 2020-August-12, 08:54