[Kaitlyn S]

MrAce, on 2016-September-24, 15:16, said:

EDIT: I am not trying to be hard on you. I say these because you may consider the spade combinations in your calculation when deciding the success rate of 5♦.

I don't consider your criticism unduly harsh. I've already misplayed this hand twice - you're just giving me an indication of just how careful I should be, and that giving my analysis in the time I would normally play the hand at a bridge table (or here on BBO without being booted by the host!) is unwise.

[MrAce]

Cyberyeti, on 2016-September-24, 16:09, said:

No I don't, I have 10 tricks for potentially +1 IMP if J♣ holds, if W wins I have at least 10 if clubs are no worse than 4-2, I may have to give up a diamond trick if W switches to hearts and the 9♦ hasn't dropped but if it has I have 11 (and W may win with Qxxx when it's better to duck particularly at IMPs, possibly thinking I might have Kxx). +3 is perfectly feasible, just needs ♣Qxx on the right on a spade lead.

On a heart lead I'm almost never going more than -2, I'll be taking the first 6 tricks then playing ♣Kx unless RHO blows on the first diamond I suspect.

Right, I forgot you already took a ♠ trick with my generous lead.

I am still waiting to hear for my point about other factors. Ignoring the under tricks vs over tricks.

Non ♥ lead is not providing you over tricks each time. Such as ♠ to A and ♥ shift. Or ♠ lead to A and continue spades, clearing your spades before you touch the clubs.
When 3 NT fails, (club finesse fails) on ♥ lead, you are down 2 much more often than down 1. Huge majority of the time when ♥ are not 4-4 you are down 2. When they are 4-4 you may still go down 2 depending on spade honors.
I already mentioned the domination of under tricks vs over tricks.
I did not mention yet the likelihood of ♥ lead vs 3 NT and 5♦. As oppose to 3 NT, in suit contracts people have tendency to lead trumps or to lead their shortness. That is a also a factor.

Only edge you have that I can think of is, on a non ♥ lead 3 NT is safe and 5♦ still needs some work but basically safe if clubs are no worse than 4-2 or 5-1 Q dropping.
On a ♥ lead, Kaitlyn roughly estimated the odds. If her estimations are true, considering the under tricks and over tricks when they both make or fail, considering the likelihood of the leads vs both contracts, I would put my money on 5♦

[johnu]

bravejason, on 2016-September-24, 07:37, said:

Was the bidding actual or contrived? If it was actual, why are you playing 5 diamonds instead of 3NT?

For one thing, this is IMPs, not matchpoints, where getting to the best game is the goal. 2nd, we don't bid double dummy in real life. Even World Class pairs get to the "wrong" game, or too high, or too low, all the time. Only BBO double dummy experts get to the right game every time. 3rd, on a different layout, maybe 6♦ is cold when 3NT is going down, etc.

[Cyberyeti]

MrAce, on 2016-September-24, 16:57, said:

Right, I forgot you already took a ♠ trick with my generous lead.

I am still waiting to hear for my point about other factors. Ignoring the under tricks vs over tricks.

Non ♥ lead is not providing you over tricks each time. Such as ♠ to A and ♥ shift. Or ♠ lead to A and continue spades, clearing your spades before you touch the clubs.
When 3 NT fails, (club finesse fails) on ♥ lead, you are down 2 much more often than down 1. Huge majority of the time when ♥ are not 4-4 you are down 2. When they are 4-4 you may still go down 2 depending on spade honors.
I already mentioned the domination of under tricks vs over tricks.
I did not mention yet the likelihood of ♥ lead vs 3 NT and 5♦. As oppose to 3 NT, in suit contracts people have tendency to lead trumps or to lead their shortness. That is a also a factor.

Only edge you have that I can think of is, on a non ♥ lead 3 NT is safe and 5♦ still needs some work but basically safe if clubs are no worse than 4-2 or 5-1 Q dropping.
On a ♥ lead, Kaitlyn roughly estimated the odds. If her estimations are true, considering the under tricks and over tricks when they both make or fail, considering the likelihood of the leads vs both contracts, I would put my money on 5♦

Spade lead away from the A will only occur in NT and you have 9 solid tricks, most often 10-12 (I suppose you might get a lead from Qxxx(x) in which case both contracts will make).

Diamond lead you will most likely only get in 5♦ and will make 11, people dislike leading stiff trumps however, but xxx will look attractive. Club lead you probably won't get against either, maybe a stiff v 5♦ which actually doesn't help much.

Heart lead is much more likely v 5♦ than 3N from some holdings (what do you lead from ♠AQxxx, ♥Qxx(x), ♦x ♣xxx(x) against the two contracts ?) and less likely from others (xxx, KJxxx, x, Qxxx), I'm not sure how to evaluate that, but a fair number of the holdings that are dangerous to 5♦ with the spades wrong, lead spades v 3N.

If W has an easy heart lead against both (KQJx for example) then 5♦ is better by a fair bit, but I'm not sure whether it's by enough. If hearts are 4-4 and you know that (4th highest 2 led for example), you still have decent chances in 3N and would need ♠AQ wrong to go more than 1 down as I think it's then correct to cash K♣ then play on spades with the odds of AQ wrong being lowered by the chance that a spade would have been led from some of the holdings and also with say Qxxx in both majors, equal likelihood of a spade lead, so you play him for the ace.

[MrAce]

Cyberyeti, on 2016-September-24, 19:17, said:

Spade lead away from the A will only occur in NT and you have 9 solid tricks, most often 10-12 (I suppose you might get a lead from Qxxx(x) in which case both contracts will make).

Diamond lead you will most likely only get in 5♦ and will make 11, people dislike leading stiff trumps however, but xxx will look attractive. Club lead you probably won't get against either, maybe a stiff v 5♦ which actually doesn't help much.

Heart lead is much more likely v 5♦ than 3N from some holdings (what do you lead from ♠AQxxx, ♥Qxx(x), ♦x ♣xxx(x) against the two contracts ?) and less likely from others (xxx, KJxxx, x, Qxxx), I'm not sure how to evaluate that, but a fair number of the holdings that are dangerous to 5♦ with the spades wrong, lead spades v 3N.

If W has an easy heart lead against both (KQJx for example) then 5♦ is better by a fair bit, but I'm not sure whether it's by enough. If hearts are 4-4 and you know that (4th highest 2 led for example), you still have decent chances in 3N and would need ♠AQ wrong to go more than 1 down as I think it's then correct to cash K♣ then play on spades with the odds of AQ wrong being lowered by the chance that a spade would have been led from some of the holdings and also with say Qxxx in both majors, equal likelihood of a spade lead, so you play him for the ace.

Sorry but I disagree with most of what you just wrote. But I do not want to turn this into your views vs my views on leads really.

Anyway, as I said earlier, if you are going to make a calculation of success rate of both contracts, you should do it fairly.

Assume you played the same hand 100 times in both contracts, and if 5♦makes on ♥ lead 10% more times (that is what you said, Kaitlyn believes 16%), that makes 10 boards which is 100 imps.( and if 16% that is 160 imps)
How many times in 100 boards, if they both make are you expecting an extra trick in 3 NT on a non ♥ lead? And how many of times when they both fail you are expecting 3 NT to fail by an extra trick? How many times 5♦ will make extra trick when 3 NT just makes?
Even if we agreed for the sake of argument and due to my generosity that when both makes, 3 NT gets an extra trick in all 100 boards(400 vs 430 in 100 boards =100 imps), you are even. Again due to my generosity, when both fails, lets assume 3 NT failed with an extra trick only 20 times out of 100. So I let you have your overtrick in all 100 boards and took extra down trick only in 20 boards. That 20 boards = 40 imps. Which brings you down to 60 imps.
Now, you have another edge, on a non ♥ lead 3 NT makes 100% of the time. 5♦ makes when clubs are 4-2 or better OR spade guess. Which is roughly around 92% . (84% + (50% of 16%) (Am I correct?)
You do the math. I know you may argue that there will be hands where you make more than 1 extra trick in 3 NT. True, But there will be hands you will not. I also believe on ♥ lead you will go down extra much more than 20%.

But please don't tell me opponents will lead a minor suit vs 3 NT after one of us opened 1 NT and other one guaranteed at least 5-4 minors. Please! (But that might be my fault that at the time I posted this hand, I had no idea explanation of 2♠ would be helpful. 2♠ guaranteed both minors, GIB cc)

[Cyberyeti]

MrAce, on 2016-September-24, 23:50, said:

Sorry but I disagree with most of what you just wrote. But I do not want to turn this into your views vs my views on leads really.

Anyway, as I said earlier, if you are going to make a calculation of success rate of both contracts, you should do it fairly.

Assume you played the same hand 100 times in both contracts, and if 5♦makes on ♥ lead 10% more times (that is what you said, Kaitlyn believes 16%), that makes 10 boards which is 100 imps.( and if 16% that is 160 imps)
How many times in 100 boards, if they both make are you expecting an extra trick in 3 NT on a non ♥ lead? And how many of times when they both fail you are expecting 3 NT to fail by an extra trick? How many times 5♦ will make extra trick when 3 NT just makes?
Even if we agreed for the sake of argument and due to my generosity that when both makes, 3 NT gets an extra trick in all 100 boards(400 vs 430 in 100 boards =100 imps), you are even. Again due to my generosity, when both fails, lets assume 3 NT failed with an extra trick only 20 times out of 100. So I let you have your overtrick in all 100 boards and took extra down trick only in 20 boards. That 20 boards = 40 imps. Which brings you down to 60 imps.
Now, you have another edge, on a non ♥ lead 3 NT makes 100% of the time. 5♦ makes when clubs are 4-2 or better OR spade guess. Which is roughly around 92% . (84% + (50% of 16%) (Am I correct?)
You do the math. I know you may argue that there will be hands where you make more than 1 extra trick in 3 NT. True, But there will be hands you will not. I also believe on ♥ lead you will go down extra much more than 20%.

But please don't tell me opponents will lead a minor suit vs 3 NT after one of us opened 1 NT and other one guaranteed at least 5-4 minors. Please! (But that might be my fault that at the time I posted this hand, I had no idea explanation of 2♠ would be helpful. 2♠ guaranteed both minors, GIB cc)

I said you won't get a minor suit lead against 3N, but might occasionally against 5♦. 3N is NOT 50%, it's a bit better than that (stiff Q offside for example, plus the chances of an obvious 4th highest of 4 heart lead which will allow it to make on the spade finesse plus stiff Q♣ either side or a void one side) so the gap is not as much as 16%.

The missing honours are also interesting, if you have to choose between Kxxx/Qxxx in the majors v 3N at IMPs, which suit do you lead ? I know I lead the Qxxx as the K is more likely to be an entry if we establish the 4th one but YMMV.

[MrAce]

Cyberyeti, on 2016-September-25, 04:09, said:

I said you won't get a minor suit lead against 3N, but might occasionally against 5♦. 3N is NOT 50%, it's a bit better than that (stiff Q offside for example, plus the chances of an obvious 4th highest of 4 heart lead which will allow it to make on the spade finesse plus stiff Q♣ either side or a void one side) so the gap is not as much as 16%.

The missing honours are also interesting, if you have to choose between Kxxx/Qxxx in the majors v 3N at IMPs, which suit do you lead ? I know I lead the Qxxx as the K is more likely to be an entry if we establish the 4th one but YMMV.

All Q onside are already counted in 50%. What you have extra is Q stiff offside, that is 1.21%

I did not understand what you meant by 4th highest of 4h lead.

[Cyberyeti]

MrAce, on 2016-September-25, 04:37, said:

All Q onside are already counted in 50%. What you have extra is Q stiff offside, that is 1.21%

I did not understand what you meant by 4th highest of 4h lead.

If you know hearts are 4-4 (like they led the 2 playing 4th highest leads and partner petered for an even number), you simply need a correct guess in spades to make 9, so play on spades not clubs as this gives you a better chance of only going -1, hence clubs 6-0 onside and any stiff Q are NOT already counted in.

[Kaitlyn S]

Cyberyeti, on 2016-September-25, 06:37, said:

If you know hearts are 4-4 (like they led the 2 playing 4th highest leads and partner petered for an even number), you simply need a correct guess in spades to make 9, so play on spades not clubs as this gives you a better chance of only going -1, hence clubs 6-0 onside and any stiff Q are NOT already counted in.

If I'm playing 3NT and I play two top diamonds and find that West had a singleton, that gives West 12 empty spaces to East's 10; meaning that each pertinent card (SA, SQ, CQ) is a 6:5 favorite to be in West. Why wouldn't I want to play for a 6-5 favorite (CQ in West)...OOOH NEVER MIND THE ODDS - If West showed exactly 4 hearts by the lead and a singleton diamond, this is a no-brainer; West is 4414 making West a 2:1 favorite to hold the CQ! It would truly be a sad play to play spades instead of clubs.

Now, let's say that West shows exactly four hearts again and diamonds are 2-2. While you don't know the club and spade distribution, you can essentially rule out West having 5 (didn't lead them) but you can't rule out East having 5; so if both players are 4423, it doesn't matter who you play for what card but if West is 3424 and East is 5422, playing West for CQ is a 2:1 favorite while playing East for a specific spade honor is 5:3, again playing clubs is the winner if only making the contract matters.

Of course, if the auction eliminated a minor suit lead, sometimes that heart lead is from a three card suit! You might lead a heart from Qxx rather than a spade from Axxx; but when you find 2-2 diamonds, this again makes West a 2:1 favorite to hold the CQ.

It gets more interesting if you find West with 3 diamonds after hearts are assumed to be 4:4 and spades are assumed to be at least 4 with East. For now, East could hold 5 spades and clubs could be 3-3. Now it seems like the spade finesse is a better shot. I would lead to the jack, as West is more likely to have chosen a spade from Qxxx than Axxx (given that the lead was the H2, West doesn't have a sequence of honors to lead from, and might have chosen a spade from Qxxx but less likely from Axxx.)

EDIT to add: Beginners, don't read this at the risk of being confused! When West is "proven" to be 4414, there could be some restricted choice issues if West is either an expert who would always choose a heart over any 4-card spade holding headed by the ace; or against a new player who "always leads 4th from the longest and strongest but even with that, I think it's hard to get above the 2:1 odds offered in the club suit.

[Cyberyeti]

Your edit covers most of I was typing. Yes if W has only one diamond it's a little more complicated but I think a spade to the J is a lot better than 50:50 due to lots of restricted choice type issues and also the ruling out of heart holdings where an honour would/might be led making a restricted choice type situation more likely where there are no spade holdings where an honour would be led.