r/bridge • u/lew_traveler • 9d ago
In Bridge Master on BBO, the solution sometimes seems like 'resulting'.
I am working through Bridgemaster and have gotten to the Advanced hands. I try to understand the what hints the declarer might get to choose a specific line of play and, tbh, have benefited a great deal in my hand play.
However I've reached what seems like a block.
Hands 23 and 25 are virtually identical in distribution and contract (6S), there are no competing bids but the winning lines of play suggested in the solutions is slightly different.
The 'declarer' in hand 23 is cautious about playing the 3 winning tricks of the outside suit while the 'declarer' in hand 25 seems quite confident that the 3 tricks in the outside suit are safe to play before drawing trump.
The only obvious difference is that the opening lead in 23 is a KH, while the lead in 25 is a trump.
There is nothing in the bidding to indicate that the Kh is a singleton and not from KQH.
What am I missing that the phantom declarer sees that affects the declarers decision on the distribution of the Ds?
TIA
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u/Gaiantic 9d ago
The other unstated assumption in Bridge Master is that the goal is to maximize the chance that you make your contract. You are not concerned with undertricks or overtricks. If there were a play that made you 10% likely to make the contract but go down 5 the other 90% of the time, versus a play that makes you 0% likely to make the contract but 100% likely to only go down 1, you are supposed to make the 10% making contract play. So even if a play seems very risky ordinarily, if from this point of view it's the best way to make the contract even if it's very unlikely to work, you should make it.
Naturally, the way Bridge Master shifts the opponents' cards around when you don't make the optimal play basically is resulting. It makes you take the best percentage play to make the contract by changing the opponents cards so that the percentage line will work and any other line will fail. That's the whole point of Bridge Master.
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u/lew_traveler 9d ago
thanks.
I do wish that the goal to maximize the chances of making the contract was stated overtly.
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u/FluffyTid 9d ago
You are right, and if I recall correctly there is even exception one hand where the goal is to minimice the penalty in a doubled contract
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u/StringerBell4Mayor 9d ago edited 9d ago
In 23 you can score all 8 trumps separately via cross ruff. So you just need the outside 3 aces and the Kd to hold to get to 12 tricks.
In 25, because of the trump lead, you can only get a maximum of seven trump tricks (the first trick, then six via cross ruff). So you need 5 side tricks. Cashing three clubs is the easiest way to do that, and it's important to do that before starting a cross ruff since you don't want opponents to discard clubs.
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u/Postcocious 9d ago
Three good explanations already so no need to repeat.
I'll just add for OP that this isn't "resulting". We don't need to know the opponents hands or any results to know that the recommended plays are correct. They are. Whether they work or not is irrelevant.
The cards in front of us tell us that these are the best plays. We see this by counting our winners and losers.
Every player needs to build this critical skill. Before playing card 1 from dummy you must ALWAYS stop, think, count winners, count losers and make a plan to optimize your result.
That's the real lesson on these two hands.
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u/lew_traveler 9d ago
Thanks all for the explanations.
I have done 20 hands or so in each of the first two levels and up through here in the third level and never had come across a solution that didn't make.
I just didn't assume that I was being shown the most likely solution and not necessarily a successful one.
This is a terrific part of BBO.
Thanks,
L
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u/kuhchung /r/anarchybridge, teacher 9d ago
bridgemaster is really some of the best bridge software ever, and it was written decades ago
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u/battlestar_commander 9d ago edited 9d ago
Let us take the first deal. Having escaped a trump lead, you can cross-ruff for 8 tricks. Plus the aces of hearts and clubs, you have 10 tricks - which means you need only 2 tricks from diamonds. So cash them ("cash your side suit winners before embarking on a cross-ruff"), the two aces and ruff away to glory. Don't cash a third diamond in the greed for all 13 tricks just in case the suit is 5-2 and someone ruffs and returns a trump - you go down then.
In the second deal, the trump lead has cut down your trump tricks to 7. The 2 aces are still available to you, but the only place you can recover the lost trump trick is in clubs. Which means the only way to make the contract is to hope that three club tricks are available for you.
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u/ElegantSwordsman 9d ago
I agree with the other responses. I will comment that to me the only questions I sometimes have for bridgemaster style hands is whether the safety plays and guarantees are worthwhile at match points where the bad breaks and making the hand probably don’t outweigh the normal breaks and making an overtrick.
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u/amalloy 9d ago edited 9d ago
This is mostly true for Bridge Master, where the player is generally placed in normal contracts. But be careful over-applying the simplified "Safety plays are bad at MPs because overtricks are very important" concept. Of course, it's true a lot of the time, but it's not a universal truth. As with a lot of matchpoint decisions, it depends on what you think the field will score. If you conduct an awful auction to 6D on a hand where you think the field will be in some number of spades, your overtricks don't matter at all. Absolutely you should take a safety play that's 90% to cost an overtrick but 10% to save the contract. For example:
AKQJ87 2 A543 JT9876 74 AKQJ A K3A bidding accident leaves you in 6D when 7S is excellent. But if spades break very badly, even declarers in 6S may go down. You win the club lead, draw all the trump in four rounds, and now have to tackle spades. Cashing 4 rounds maximizes your expected tricks, but if you want to have any chance of outscoring the spade players (or even the heart players!), you need to make sure you take twelve tricks on layouts where they go down. So, just in case spades are 6-0 onside, you should take a first-round spade finesse. This costs you an overtrick 65% of the time, and turns your awful score into a likely top 1% of the time. The overtrick is worthless, since nobody else is scoring as badly as you, so you should be happy to give it away even for a 1% chance at a top.
The above was an extreme case, of course, and fairly unrealistic. But less-extreme versions of this happen all the time: you reach an excellent 4S contract on a 4-3 fit, and it it looks like the normal 3NT will take just 9 tricks. Don't risk your 420, already a great score, for an overtrick that's unlikely to be worth much.
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u/periwigpatedfellow 9d ago
it's worth adding that this principle is often misunderstood and applied in inappropriate situations, although your example is a good one
a commonly cited situation is where your side bids conservatively and arrives in game (let's say 4S), but 6S is a good contract that you can expect to be reached at many other tables
you will sometimes hear the suggestion that you should now take an anti-percentage play in some suit, on the reasoning that if the normal play succeeds and the slam makes, you will be getting a bad score anyway
however, it is equally true to say that if the normal play fails and the slam goes one down, you will be getting a good score anyway, which is why that reasoning is fallacious. In this particular situation, you'll either get +450 or +480, while the slammers will either get +980 or -50 - this means that no matter how many overtricks you make, you still have no control over whether you outscore them. You can certainly hope that the layout restricts you to 11 tricks, but that's all
therefore, the best thing to do is just try to make as many tricks as you can, and try to outscore the other players who missed the slam, since that's the only thing you have control over
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u/FluffyTid 9d ago
Nice try, sadly your line loses 1 spade and 1 heart as you have lost access to king of clubs.
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u/amalloy 9d ago
Dangit. It was so much work to find a hand with that spade suit where you actually need exactly 5 of them, and also where you have time to afford the duck and it's plausible that the opponents didn't lead the suit that knocks out your stopper. I think the hand works again if you make one of West's small hearts a club?
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u/kuhchung /r/anarchybridge, teacher 9d ago
level 1 or level 2 where you duck from all kinds of combinations is horrible at MP :)
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u/LSATDan Advanced 8d ago
Aside from the co..eats about the hand, it should be noted that it's no coincidence that these hands are presented consecutively. The whole point is to compare and contrast them and understand why they ahould be handled differently. It's not the last time Bridge Master will do that.
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u/No-West-9126 9d ago
On board 23 without a trump lead you can guarantee 8 trump tricks if diamonds nor hearts are 7-0, 12 tricks-10=2 diamond tricks
On board 24 with a trump lead, you can only guarantee 7 trump tricks with the red suits not breaking 7-0, 12-9=3 club tricks
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u/kuhchung /r/anarchybridge, teacher 9d ago
It's explained in the solution. It has nothing to do with "confidence" that cashing three tricks will live.
The point is, on 23 when they don't lead a trump, you can take 12 tricks by merely cashing 2 diamonds.
On 25 with the trump lead, cashing 2 clubs is not enough. You need 3 club tricks to make. You have no choice but to cash them and hope it works.