[bluecalm]

Quote

remember that aces are worth a little more than 4, not less.

And that 2 tens are worth a bit less than a jack and 3 tens are worth a bit more than a jack, at least when it comes to NT. I remember 0.4pc mentioned somewhere for tens and some positive adjustment for having 2+ aces. I remember simulating a lot of hands and that seemed correct. Also my very limited experience tells me this is about right.

[blackshoe]

That Aces and Kings are worth less, and Queens, Jacks and Tens more, than Work suggests is one of the surprising things, say the authors, about the Banzai count. But they accept it, and move on. I dunno, maybe they're wrong. It surprised me too.

Someone upthread commented about the "four lone aces" example being, willy-nilly, a strong NT, and any count that calls it weak is (my words, not the someone's) crazy. But is it? Four aces is four tricks, and I would think a strong NT ought to give you, on average, six or so. Am I wrong?

[mgoetze]

blackshoe, on 2012-June-21, 12:14, said:

Four aces is four tricks, and I would think a strong NT ought to give you, on average, six or so. Am I wrong?

Yes, you are.

How many tricks is KQxx KQx KQx KQx? Also four?

[aguahombre]

This thread is frightening me. I find myself in total agreement with Mike.

[blackshoe]

mgoetze, on 2012-June-21, 15:41, said:

Yes, you are.

How many tricks is KQxx KQx KQx KQx? Also four?

Somewhere between four and eight, inclusive.

How many tricks is a strong NT worth?

[helene_t]

blackshoe, on 2012-June-21, 18:30, said:

Somewhere between four and eight, inclusive.

How many tricks is a strong NT worth?

But the whole problem with Banzai is that the number of tricks taken in your hand in the particular suite is not everything.

Sure, if you pick up an average 15-17 hand you expect that your hand will take more than four tricks so in that sense A32-A32-A32-A432 is disapointing.

On the other hand, your aces increas the likelihood that partner will take tricks. A king of his which would be half a trick without your supporting ace (a little less since he might be forced to lead away from it), now becomes a sure trick. JT974 which would likely give hime zero tricks without your supporting ace now has a good chance of giving three tricks if he has two entries.

Then there is the issue of tempo. Axx can be held up twice which may be enough to break opps' communication but you can also chose to take the trick immediately if you fear a switch. With QJT you don't have that flexibility.

AKxx is only two tricks but opposite xxxx you likely have a length trick also. QJT9 has only two tricks opposite xxxx.

This all becomes very complicated but fortunately there is a very simple solution. Just take a large number of deals with corresponding numbers of tricks taken (DD, Jack, Bermuda Bowl, Bridgebrowser, whatever) and then fit some regression model. This is easy to do and it gives you relevant results.

[gwnn]

Yes, Helene, but if you haven't read the book then you are not allowed to use reason, mathematics, logistic regression, anything. In fact if you haven't read the book you are not even allowed to post anything. Playing bridge is allowed but you will almost surely fail.

[mgoetze]

blackshoe, on 2012-June-21, 18:30, said:

Somewhere between four and eight, inclusive.

How do you take 8 tricks with this hand?

Let's try a different tack.

Your hand: Axxx Axx Ax Axxx

Partner's hand: x xx KQJxxxxx xx

How many tricks is your hand "worth"?

[blackshoe]

helene_t, on 2012-June-22, 02:07, said:

But the whole problem with Banzai is that the number of tricks taken in your hand in the particular suite is not everything.

See below.

gwnn, on 2012-June-22, 02:49, said:

Yes, Helene, but if you haven't read the book then you are not allowed to use reason, mathematics, logistic regression, anything. In fact if you haven't read the book you are not even allowed to post anything. Playing bridge is allowed but you will almost surely fail.

Your sarcasm is dripping all over the floor. Better clean it up.

mgoetze, on 2012-June-22, 05:27, said:

How do you take 8 tricks with this hand?

Let's try a different tack.

Your hand: Axxx Axx Ax Axxx

Partner's hand: x xx KQJxxxxx xx

How many tricks is your hand "worth"?

My hand is worth four tricks. Partner's hand is worth six or seven tricks, if he can ever get back in after knocking out the A and maybe the ten. It might be worth no tricks. Our hands together are worth 11 tricks. If your point is that it's the tricks the two hands together can take that's important, I agree. But I don't see how Work does a better job at that than Banzai does. Seems to me they both have the same flaws in this respect.

If somebody suggested that 5-4-3-2-1 is a better scheme than 4-3-2-1-0 or 4-3-2-1-1/2, and didn't tell you that those numbers are based on an analysis that doesn't take into account whole hands, would you all still be so negative about it? For that matter, did the analysis on which Work is based (was there such an analysis?) take into account whole hands?

[Statto]

the hog, on 2012-June-20, 20:05, said:

Statto's comments lack the same credibility.

Fair point. However, like Han, I have done some analysis.

Correlation between combined 'point count' and number of tricks makeable DD declaring in NT, over 100,000 deals, for various evaluation methods, when both of the pair are balanced (4333/4432/5332, 24% of deals) is as follows:

Milton adding ½ for tens (from 42 point deck) - 0.914
Milton - 0.912
Banzai - 0.900
KnR - 0.899

Analysis of the pure value of high cards for NT over the same balanced combinations from the random deals gives (for a 40 point deck):
A = 4.005
K = 2.821
Q = 1.688
J = 0.890
10 = 0.361
9 = 0.173
8 = 0.061

If we include all deals (including the vastly unbalanced) in the analysis of card value for NT, we get:
A = 4.276
K = 2.761
Q = 1.574
J = 0.837
10 = 0.365
9 = 0.158
8 = 0.030

For better analysis, we need a single dummy solver, but I'm not aware of one. I'm sure that in DD analysis Queens tend to be undervalued, due to the 2-way finesses always being right, etc.

[Zelandakh]

Any chance of running the same analysis but separating out a queen or lower with another honour versus without and also singleton versus doubleton versus 3 or more? I think you should also separate out a singleton ace or king versus 2 or more. Ideally we would analyse all honour combinations rather than individual honour values here I think. Indeed I thought this had been done by someone a while back but if so I cannot remember any significant results from it (other than the normal stuff anyway).

[gwnn]

http://www.bridgebas...s-investigated/ has some fun stuff. Oops, suit contracts.

[Zelandakh]

gwnn, on 2012-June-26, 01:29, said:

http://www.bridgebas...s-investigated/ has some fun stuff. Oops, suit contracts.

I have seen a lot more analysis on suit contracts, mostly because of the shake-up that Zar points caused. I have not seen so much detail devoted to NT contracts, probably because Milton is good enough here and there is less scope for improvement. Nonetheless, I think such an analysis would be interesting and could (theoretically at least) produce a set of "standard" upgrades and downgrades which would be great for both B/I players and perhaps also computers. Of course, on a personal level it would also be of great interest to see how my own list of amendments fares against reality.

[bluecalm]

Quote

For better analysis, we need a single dummy solver, but I'm not aware of one.

Double dummy solver with single dummy leads would be a big step in this direction. You would define what information the opening leader has from the bidding and amount of tricks would be determined after the program chooses 1st lead on every hand. Even if it requires simulating 100 additional hands just for lead decision it's entirely viable on modern hardware (it seems available simulators these days don't even do simple parallelism which would instantly speed them up by a factor of 4/6/8 and hands for the lead simulation could be dealt in such a way to make solving faster (spots closer together)). Besides that determining decent 1st lead could probably be implemented decently without any simulations.

I still hope someone writes one before I do

[cherdano]

blackshoe, on 2012-June-22, 21:29, said:

If somebody suggested that 5-4-3-2-1 is a better scheme than 4-3-2-1-0 or 4-3-2-1-1/2, and didn't tell you that those numbers are based on an analysis that doesn't take into account whole hands, would you all still be so negative about it? For that matter, did the analysis on which Work is based (was there such an analysis?) take into account whole hands?

Imagine playing a game of money bridge with the following set up: In odd boards, I will be dealt a 4333 with 4 aces. In even boards, you will be dealt 4333 with QJ QJ QJ QJ. All other hands are random. Only NT contracts are allowed.
Since this is replacing an Ace by QJ in the same suit, rather than by Qxx Jxx, this is actually a very favorable setup. In addition, my aces aren't supporting any lower honors. So, if you think Banzai count is reasonable, QJxx QJx QJx QJx will win a lot of money against Axxx Axx Axx Axx. Fancy a game?

I think what you are missing that the judgment of good bridge players is much much finer than just using point count. They don't just use point count, they also have an intuition which hands are slightly undervalued or overvalued by point count. If Banzai points were right, than someone would have found out you can win by upgrading hands with many queens and jacks.

[aguahombre]

...

[blackshoe]

cherdano, on 2012-June-26, 04:30, said:

If Banzai points were right, than someone would have found out you can win by upgrading hands with many queens and jacks.

Hm. Okay, that seems to make sense.

Interesting. I took Statto's 'pure value' numbers and normalized them to 4 and 5 for the ace. Got:

A-4.000, K-2.817, Q-1.686, J-0.889, 10-0.361 = not much different from the pure numbers, unsurprisingly.
A-5.000, K-3.522, Q-2.107, J-1.111, 10-0.451 = this looks to me like a 5-4-2-1-1/2 count, and a 50 point deck. But I probably have no clue what I'm talking about.

[Cthulhu D]

That would make sense and supports the view that work tends to slightly overrate Qs +Js. To take the Axx Axx Axx Axxx equivalence above, now the equal hand is KQJT KQT QJT QJT and that's possibly equivlent.

3NT is cold opposite xxxx Axx Axx xxx or xxxx Jxx Kxx Kxx which is about the least partner could have to drive to game

[bluecalm]

To take the Axx Axx Axx Axxx equivalence above, now the equal hand is KQJT KQT QJT QJT and that's possibly equivlent.

Intuitively the 2nd one is much stronger. I mean, it would make 3nt opposite 8hcp balanced more often (and by a lot).
If someone feels I am incorrect here I can run a simul.

[Cthulhu D]

bluecalm, on 2012-June-26, 09:35, said:

To take the Axx Axx Axx Axxx equivalence above, now the equal hand is KQJT KQT QJT QJT and that's possibly equivlent.

Intuitively the 2nd one is much stronger. I mean, it would make 3nt opposite 8hcp balanced more often (and by a lot).
If someone feels I am incorrect here I can run a simul.

Probably need to add in a bonus for honour sequences.