AL78

It is hard to say. I'm getting equally crap results online as I did in the physical club, so I guess that means I am playing just as well or as badly. I think it is harder to fully focus in front of a screen because when I am trying to work out the layout, I stare hard at the cards whilst doing so. Doing that in front of a screen can give me a headache so I try to avoid doing it, which may result in a reduction in working things out. I do know that if the club went online permanently and never re-opened its premesis, I would resign.

On this forum, there are people posting from many different countries which have different standard systems. For example, in the UK, Acol is the most common system played at club level and a 2 over 1 minor response only promises four cards minimum and a good 9+ HCP. In the U.S, they play a game forcing 2 over 1 which I am not familiar with and I don't know whether a 2 over 1 always shows a five plus card suit. If someone in the UK is playing that 2 over 1 promises at least five cards whatever the suit, they would have to reveal it to their opponents (probably through an alert and/or stating it before play). I play 5CM with my partner in the UK and in an auction like 1♥ (P) 2♦, the 2♦ shows 4+ diamonds.

The East hand is big when West can respond at the two level in a suit they hold Qxx. I would bid 2♠ on the second round, which is a game force if you are not playing 2/1.

I think you have misread the auction. The North hand is not the partner of the opener, it is sat over the opener, thus the question is what do you call with that hand after RHO opens 4♥. On board 10 I'd gamble a double if that is value showing do-something-sensible-partner. If it is strictly takeout, I'd pass and hopefully take a plus score. Board 18, 6♥.

https://dictionary.cambridge.org/dictionary/english/obnoxious

This was the full deal: [hv=pc=n&s=saq63hk2daq4ckj65&w=sk9842hq653d9cq43&n=sj75hj974d73c9872&e=sthat8dkjt8652cat&d=w&v=e&b=16&a=pp1d2n3sp3ndppp]399|300[/hv] Playing on the black suits seems to work best. Club leads don't give declarer anything he can't get himself, and partner does have four clubs with you so you can set up two club tricks, which is enough to take it off. A spade lead sort of works as well, although if you lead the ace, when declarer plays the ten, you have to guess whether it is a singleton or does he have JT doubleton. If you get it right you can set up one extra spade trick, and there may be opportunity later in the play to endplay dummy.

You are a factor of 10 out, I make it 0.04%. It is more likely that I would have thought, about the same magnitude as picking up a Yarborough or an Acol 2♣ opening.

Surely it is 0.732097^25, the probability of the event happening 25 consecutive times. What you have is the probability of getting more than 12 HCP 25 consecutive times.

I meant to add its matchpoints.

A novice friend of mine had a bad evening and I looked at her bad scores. This hand stood out as being a nightmare to defend with. The opponents were playing some version of Acol, weak NT. [hv=pc=n&s=saq63hk2daq4ckj65&d=w&v=e&b=16&a=pp1d2n3sp3ndppp]133|200[/hv] She didn't know what to do with a balanced 19 count over the opening bid, so bid 2NT thinking that showed a stronger hand than overcalling 1NT (I have since explained how to show a hand like this after RHO opens, and how a lot of people play a jump to 2NT). They ended up letting it through. Apparently on the last five tricks, South cashed her last diamond stop and then played a club to declarer's ace, allowing him to take the remaining tricks. Aside from that, the question is if you are defending 3NT with this hand, how would you go about planning the defence, knowing partner is marked with a bust and you will be leading out of your strength frequently?

The probability distribution for the HCP for a single hand is a discrete distribution, the density function is given in this table: https://www.bridgebum.com/hcp_distributions.php From this table, I think there are statistical formulae which can be used to calculate the probability of getting an average HCP of X over 25 deals, but they escape me at present. An average HCP of 7.48 over 25 boards is equivalent to a sum of 25 x 7.48 = 187 HCP. It should be possible to work out how many ways there are to combine 25 hands to get less than or equal to a cumulative total of 187 HCP, then work out the probability for each combination, finally summing them all.

This reminds me of a friend of mine who averaged 7.17 HCP over 18 boards. She declared twice, was dummy twice, and defended 14 out of 18 hands. This is the lowest HCP average I have seen over a session (even lower than my worst).

It is also what other people do with the cards you are dealt (at duplicate), which you have no influence over. If your opponents punt a slam on a hook and a 3-2 trumpm break which no-one else bids, you are getting a bottom or a double figure negative IMP score whether you like it or not.

The question was not about the probability of picking up one hand with a specific HCP, it was about having a mean of a specific HCP (or less) over a session with 25 hands. We are interested in the distribution of means of 25 randomly sampled hands, which will approach normal as the sample size gets very large. You see the same in the UK national lottery, the distribution of the mean sum of the six randoms numbers selected is extremely close to normal if evaluated over all possible random samples, even though the distribution is bounded, so statistical inferences which assume normality of the distribution can still be used. https://en.wikipedia.org/wiki/Central_limit_theorem

The number of possible bridge hands is finite so it theoretically is possible to calculate exactly the probability of getting less than or equal to a HCP average over some number of boards. You can get an approximation by randomly dealing a large number of hands and working out the mean and standard deviation of the mean HCP of 25 hands. Although the mean is bounded, the central limit theorem states that the distribution of the means approaches a normal distribution for large sample sizes, so you can compute the mean and standard deviation of the mean HCP of a large number of groups of 25 hands, assume this closely resembles the full population distribution, and use the normal cumulative distribution function to calculate the probability of exceedance. It is recommended you use a computer to generate the random deals.

I'd be tempted with a heart lead at imps or maybe a spade lead. The opponents haven't shown any interest in the majors, so it is not asking for the world that partner has something useful in one of them. At MPS, I have no idea, it is the hand of death where any lead could blow a trick, there is probably one good lead and two bad ones. Can't see it is anything more than a guess, although I'd likely lead a major for the reason given above.

I assume you mean Axx Kxxx Ax KJTx. Opener cannot hold the heart ace as you have it.

After a bit of thought I decided to gamble 3NT. I decided the odds of partner having one or two dimaonds and the queen and jack coming down, or partner having Qx was sufficiently high to make it a decent shot. The full deal: [hv=pc=n&s=skj94hq2d86ckq742&w=st732hkt5dj7cat63&n=sa6hj987643dqc985&e=sq85hadakt95432cj&d=n&v=e&b=9&a=3h3nppp]399|300[/hv] After a heart lead, the diamonds run for eight tricks, two top hearts and the club ace, and some faulty discarding which gave me an 11th trick, +660 and an 88% board. Only one other East out of 13 bid it, most were bidding 4♦ making 10-12 tricks (mostly 11). One lucky East was doubled in 5♦ which made. Tough for the defence, South has to lead a low spade and it goes A, J, K, has to be done immediately or never. A couple of NS pairs found the good 5♥ sacrifice (undoubled).

Assuming RA means Regional Authority, assume yes.

Matchpoints, vul against not. RHO as dealer opens 3♥. You hold: ♠Q85 ♥A ♦AKT95432 ♣J Your turn.

I'm guessing Acol based, weak NT.

I would if playing a strong NT or opened 1♦ followed by 1NT if playing a weak NT. I wouldn't have classed the hand as good enough to reverse.

I have tried another solver and yes it does say slam makes. The lead was the ♣2. I didn't like the option of ruffing clubs at the time because it meant possibly generating a trump loser, so when the finesse worked and they broke 3-2, I have to make three heart tricks, which I thought I had good odds to manage, but not this time. I struggle to find the best line on these messy hands with limited communication and blockages.

I didn't get a heart lead. I drew trumps before playing on hearts, I played small to hand and LHO played the ten, so I covered and didn't have an entry back to dummy, so had to play for the 3-2 break which wasn't forthcoming. I should have played only two rounds of trumps before touching the hearts, then I have a trump entry to play to hand twice. I put this hand through an online bridge solver and it says EW can only make 3♠ on double dummy defence. Apparently, despite the double major fit, the only double dummy game on is 3NT. I would not have found the brilliant line after a heart lead. That is up there with the Expert and World Class deals on Bridgemaster which nearly always take me multiple attempts or I have to look up the solution.

No. I didn't know you could play lebensohl in that situation.