[pescetom]

Yesterday in the last round of a Team Tournament partner opened 2NT (20-21 HCP, was actually 20) and I held 10 HCP. Both hands were flat 4333 shapes with no major fit, we bid 3NT which made with 3 overtricks thanks to the opps having the K♠ under impasse and the clubs split 3-3.

When all was finished I wandered over to the table where the scores were being tallied and saw my team-mates looking distraught. At the other table opps had bid and made 6NT, which resulted in a huge IMP swing and put us out of the prizes. Nobody said openly that we should have taken the same shot, but the suggestion was clearly in the air. Of course they wouldn't have been thrilled if we were the only ones in 6NT-1 either, and that looked likely to me.

This had me wondering what the odds of making 6NT with two flat hands of 20 HCP and 10 / 11 / 12 HCP actually are. If anyone has a simulation of that or a table that helps I would be grateful.

[Stephen Tu]

So your opponents bid an 18% slam, that sucks, but that's bridge.

Pavlicek published some results
http://rpbridge.net/8j25.htm#

that suggest 31 HCP combined is good enough for a reasonable shot (if not off 2 aces of course), but I think given the double dummy nature of always finding queens, picking right way to finesse/dropping them offside/choice of finesse vs squeeze etc. it probably needs closer to 32 in practice single dummy.

[pescetom]

Stephen Tu, on 2018-August-12, 10:49, said:

So your opponents bid an 18% slam, that sucks, but that's bridge.

Pavlicek published some results
http://rpbridge.net/8j25.htm#

that suggest 31 HCP combined is good enough for a reasonable shot (if not off 2 aces of course), but I think given the double dummy nature of always finding queens, picking right way to finesse/dropping them offside/choice of finesse vs squeeze etc. it probably needs closer to 32 in practice single dummy.

Thanks Stephen. 32 HCP combined and 3 Aces is about where I would have set the bar if taking a reasonable shot at MP, but I'm less used to team tournaments and I was conscious that I was not captain either.
If I interpret RP's table correctly then the odds of making 6NT are 33% for 20-10 and 53% for 21-10 (accepting an invite). That's more than I expected although as you say these are double dummy numbers and his definition of Balanced covers more shapely hands than these.

[Stephen Tu]

pescetom, on 2018-August-12, 11:31, said:

Thanks Stephen. 32 HCP combined and 3 Aces is about where I would have set the bar if taking a reasonable shot at MP, but I'm less used to team tournaments and I was conscious that I was not captain either.

For bidding small slam vs. not bidding small slam, there's no diff between IMPS and MP. Because IMP loss when wrong = IMP gain when right. This is unlike game bidding especially vul game bidding. MP just put more emphasis on getting to the correct slam if bidding it, as often being in NT or M instead of minor may be crucial if field is in slam.
IMPS: more aggressive than MP for bidding game, way more aggressive when vul. Small slam bidding vs stay in game: same. Grand slam bidding: more conservative than MP.

[mcphee]

A look at the imp scale should help you see a 50% slam is not a winner, (unless your finesses always work), compared to the imp swing for reaching games which are far less than 50%.

[mikeh]

In fact, a '50%' slam is rarely a '50%' slam. Often (tho by no means 'always') the '50%' slam actually assumes, for instance, that AKQJx opposite xx (or the equivalent with honours in the short suit) is worth 5 tricks. Of course it usually is but every now and then the suit breaks 5-1 or even 6-0. In a similar vein, a suit contract that appears to be on a finesse may in fact fail due to a ruff at trick one when a suit breaks, say, 6-0.

Finally, on a few occasions the 50% slam can effectively be doubled, although (depending on the result at the other table) the increased penalty doesn't result in an increased swing.

Hence, unless you can assuredly count 12 winners 'if the hook wins', the 50% slam should be avoided, since in the long run it will prove to be a modest losing proposition. If you can count the requisite tricks as a sure thing, then you can bid or avoid the 50% slam as the mood moves you...in the long run bidding slam and staying out will be flat.

Edit: the fact that your teammates appeared to blame you for losing says a lot more about them than it does about you, and nothing flattering.

[rmnka447]

Stuff happens at the bridge table. This time the bridge gods favored your opponents who bid a decidedly low percentage slam that made. There's nothing you can do about it. They got lucky.

If your teammates are in a huff because you didn't bid it, then maybe you need to think about getting new teammates. It sounds like they are result merchants who judge their partners play solely on the results. Good teammates would acknowledge that you made the right decision NOT bidding the slam and move on.

[Phil]

50% is precisely the right number for a major or NT slam.

The proof is: 12 tricks: 1430 / 980 vs 680 / 480 = 13 or 11 IMPs.

11 tricks: -100/-50 vs 650 / 450 = 13 or 11 IMPs.

A minor suit slam is a little less than 50% however. You can prove it out like above.

[barmar]

mikeh, on 2018-August-13, 11:04, said:

Hence, unless you can assuredly count 12 winners 'if the hook wins', the 50% slam should be avoided, since in the long run it will prove to be a modest losing proposition. If you can count the requisite tricks as a sure thing, then you can bid or avoid the 50% slam as the mood moves you...in the long run bidding slam and staying out will be flat.

Unless your counterparts at the other table are timid players who only bid sure slams, they're probably going to discount the other factors as well. Doesn't history show that it pays to be optimistic in bidding? Aggressive bidding puts pressure on the opponents, and there are plenty of cases where the opponents slip up on defense and you make impossible contracts. Maybe there are fewer opportunities for this in slams, but it happens.

[pescetom]

Thanks all for the maths and the consolation
Of course in this situation we were two teams both on the edge of the (money) prize zone so I can see a case for taking a last-round shot, if that is the team mentality (the opponent who called slam knew he was taking a huge risk). Part of my discomfort was that we hadn't discussed this previously and not being team captain I didn't feel authorised to take such a shot, at least with what I thought looked like grim odds.
I'll be meeting the team again tonight in a MP tournament, so I guess I'll find out if I am in disgrace now that they've had time to think it over - I trust not.

[Stephen Tu]

barmar, on 2018-August-14, 09:13, said:

Unless your counterparts at the other table are timid players who only bid sure slams, they're probably going to discount the other factors as well. Doesn't history show that it pays to be optimistic in bidding? Aggressive bidding puts pressure on the opponents, and there are plenty of cases where the opponents slip up on defense and you make impossible contracts. Maybe there are fewer opportunities for this in slams, but it happens.

Very good player told me "bid sketchy games, not slams". Save aggressive bidding for game bidding, and competitive bidding generally. Not constructive bidding to super thin 50.x% slams.
For slams, gain your edge against weaker opps by having good methods to find good fit slams on few hcp that are laydown or like 60+%, and not getting to 40% or whatever ones.
In my experience going for the very thin ones leads to a lot of 34% ones (you need finesse + 3-2 break) and 42% ones (finesse and some suit 4-2/3-3) and a good way to blow the edge you have on other boards.
On thin slam hands there are generally way more opportunities for declarer to screw up than the defense.

[barmar]

But bidding slams is so much fun!

[pescetom]

barmar, on 2018-August-15, 09:06, said:

But bidding slams is so much fun!

Especially when we get to bid a good slam that the others missed

My team-mates turned out to be completely absorbed in the current tournament and with no desire to rake over the past.
Which was fine by me, so we all played merrily until another controversial opportunity loomed up...
but that deserves a topic of it's own.

[Cyberyeti]

barmar, on 2018-August-15, 09:06, said:

But bidding slams is so much fun!

The biggest win of my career was in a gold cup match where we were nobodys playing a highly seeded team in a 48 board match, second set of 8, we picked up 2 on the first.

One of their pairs bid 3 sub par slams, none of which made. We picked up 63 on the set of 8, and even though they won all 4 remaining sets, the last one by a lot, they couldn't retrieve enough.