[whereagles]

Winstonm, on Apr 1 2005, 01:14 PM, said:

I haven't bothered to figure it out, but I'd guess about 60-70 percent of the time that a 1NT opening is passed out that it is a normal contract, just arrived at quicker than by those opening in a suit. That means that a decent amount of time the 1NT bidders will be in the wrong contract. They may get a slight edge overall in the partscore battle, but IMO that goes up dramatically if one gets overactive against them.

The logics is good, but incomplete.

1NT being a bad contract 30-40% of the time might be true, but 1NT is also hard to defend and prone to bad leads from defenders. I'd say that makes it a wash-out.

[Winstonm]

Quote

1NT being a bad contract 30-40% of the time might be true, but 1NT is also hard to defend and prone to bad leads from defenders. I'd say that makes it a wash-out. 

I agree. Furthermore, the opening and responses made by the big no-trumpers give more information away as to what is the best lead if they settle in 1NT; however, to compensate for that there are the times when a 4/4 major is missed with responder holding a weakish to middling hand - both contracts may make but an imp may be gained by playing 2S instead of 1N.

I agree a wash is about right - unless one gets too active against the weak no-trumpers. IMO, mixing it up too much with the weak NT will give the weak NTers a clear advantage.

WinstonM

[hotShot]

Some numbers i got by simulation (1000 boards) regarding NT contracts:
Edit: 1rst seat opening, no 5M, at least 2 cards every suit


range: 15-17 about 4-5% of the openings
After an opening of 1NT:
declarer makes 7+ tricks in NT 34/46 times
declarer makes 6+ tricks in NT 41/46 times, so not often more than one down.
declares side can make 8+ tricks 41/46 times (any contract)
declares side can make 7+ tricks 45/46 times (any contract)
so if they run from 1NT they usually make ther contract.

range: 12-14 about 10% of the openings
After an opening of 1NT:
declarer makes 7+ tricks in NT 67/104 times
declarer makes 6+ tricks in NT 79/104 times
declarer makes 5+ tricks in NT 95/104 times
declares side can make 8+ tricks 82/104 times (any contract)
declares side can make 7+ tricks 95/104 times (any contract)
declares side can make 6+ tricks 100/104 times (any contract)
about 2/3 times they can make 1NT, 3/4 of the times they make what they run to.
Usually they won't go down more than 2.


range: 9-13 about 21% of the openings
After an opening of 1NT:
declarer makes 7+ tricks in NT 106/218 times
declarer makes 6+ tricks in NT 126/218 times
declarer makes 5+ tricks in NT 174/218 times
declares side can make 8+ tricks 145/218 times (any contract)
declares side can make 7+ tricks 177/218 times (any contract)
declares side can make 6+ tricks 200/218 times (any contract)

They can make 1NT less than half of the time, but if they run the chance to make a 2 level contract is about 2/3. If they run, they have a better than 90% chance not to go down more than 2.

[luke warm]

i have no idea what all that means, so i'll just stick to my weak nt until i can once again find someone willing to play the mini

[hotShot]

Thank you for pointing that out luke.
I thought the facts speak for themselves, perhaps they don't.

It says:
Playing strong NT is safest. You get a hand for it once in 20 times you are declarer. You will make 1NT about 75% of the time. You will seldom be more than one done. Considering that the double dummy solver does not give away a trick on lead, you might be even better.

Playing weak NT is less of a risk than people might think.
You will make 1NT+ 65% of the time. If opps double and you run, there is a suit 80% of the time, that lets you take 8 or more tricks.
You won't loose more than -1 in NT 80% of the time, playing a suit on 2 level you can tune it up 90+%.
Assuming that that you play MPs, one down is often better than a partscore your opps could get. Again considering that the double dummy solver does not give away a trick on lead, you might be even better.

Playing Mini-NT does not pay off against good opps at IMPs.
You won't make 1NT more than half of the time. There is a 30+% chance of going down 2. Running to a suit on 2 level will improve your chance to 55+% to make the contract and there's a 80% chance to go down just one. So if opps dbl you better run, and opps have a good chane to score well, if they dbl that too holding a decent hand. Weaker opps at MP, might give you an extra trick for a good result.

[awm]

One can look at these statistics a bit differently. I think they actually support my belief that mini notrump is excellent at nonvulnerable, but strong notrump is best at vulnerable.

The basic observation is, playing the mini you will often end up going one down. However, you will rarely be tagged for more than two off. At nonvulnerable, one down is good bridge. Down two undoubled is fine. Down two doubled, well, opponents may have a game, in which case you have a sizeable win. Even if they don't have game, they have to find a double.

On the other hand, at vulnerable, even with 12-14 you will end up going down one in something ten percent of the time, and two off will be unavoidable about one time in twenty. Often you will be doubled in these situations, and it will very rarely be a good result. The mini at vulnerable is pretty much suicide against good players.

[joker_gib]

I play 12-14 NV and 15-17 V for 2 or 3 years now and I'm very happy with it

Alain

[Chamaco]

hotShot, on Apr 13 2005, 08:16 AM, said:

Thank you for pointing that out luke.
I thought the facts speak for themselves, perhaps they don't.

.....................

One very important consideration is whether you are opening weak/mini in 1st/2nd seat (unpassed pard) or 3rd/4th seat.

Opening weakNT with an unpassed pard makes life MUCH harder to LHO when he holds a good hand: if he passes, he risks mising game, if he bids, he might be trapped if our pard is strong.

Weak/mini NT in 3rd position reverses the odds:since both our pard and RHO passed, LHO may choose to bid without great risk, or offer to double.

[hotShot]

I looked at 1rst seat openings only, for the simple reason that it's a lot of conditions to rule out all posible openings in 1rst and 2nd seat. Not to mention that it depends on the system played. But in general i think that the odds for a succesful weak NT rise in 3rd seat. There are 2 possible cases:
1) Your LHO is very strong.
2) Points are evenly distributed among the other 3.

In case of 2 your odds to make 1NT or something on 2 level rise.
But maybe i'll look into it using simple SAYC openings.

The chance that opps can make game (assuming perfect declarer play) after a weak NT 1rst seat opening, is about 14%. Guess that means that most of the time you loose by 2 +tricks good opps could make full game.

[Winstonm]

A couple of odds and ends. When I have played weak NT, I used DONT as an escape mechanism. It worked fine with xx replacing x as a 1 suiter.

Second, a disadvantage of the weak NT no one talks about is having to open the 15-17 NT with a minor. This allows cheap overcalls to be made which can dramatically affect the future outcome of the hand.

WinstonM

[Stephen Tu]

hotshot wrote:

Quote

You will make 1NT+ 65% of the time. If opps double and you run, there is a suit 80% of the time, that lets you take 8 or more tricks.

Eh? This can't possibly be right. I don't think you are interpreting the statistics properly. Didn't your simulation determine that the opening side can take 8+ tricks somewhere ~80% of the time? *But that includes large number of hands where they don't double you*. A lot of these hands were ones where your side just bids uncontested to your partial or game. When 2nd hand does have a double, the percentage of success of both 1nt or a runout is going to drop drastically. Run the numbers again given a 1st seat 12-14 NT opener, and 2nd seat 15+. Use a larger # of boards, also.

I like the weak NT. You don't get penalized that often, and the opponents get themselves in trouble probably more often than they get you. But if you are doubled, you are often in trouble. There's no way you have a successful runout 80% of the time. The opponents will often let you off the hook when you run, but that's their error, not that the runout would have been successful.

You might make at least 2 of a suit 80% of the time overall, but not 80% of the time after they double.

[mycroft]

My weak NT experience:

Pd and I were known to be stable team players. I.e. we almost never came back with a "we lose, no matter what you did" card. Of course, we rarely came back with a "we win, no matter what you did" card...We got very good partners for team games because of this - they knew that if they felt they won the match, we weren't going to number them out; and if they felt they lost it, we wouldn't bring back a 0-30, and we might just save them.

When we did bring back "we win" cards was when our weak NT got overcalled, and we were +500 or more into nothing. I can't remember more than once that we got nailed for a big number when they had no game - my favourite was 2C-4 for a push (teammates: 3NT=); they couldn't double because we were max. 200 in hearts and we would find it.

I will admit we were playing an unusual for the region method, so the opps probably weren't as experienced against it than say the Brits...but I stay by my statement: when we brought back "we win" cards, it was because they walked into an axe overcalling our 11+-14 NT. And we *were* experienced about when to lower that axe.

At MPs, we got nailed by the "anti-field" syndrome: 1NT= vs 2M= after 1m-1M; 2M. At IMPs that was a wash.

I also say "I'll play anything you like against NT, but I get to double a weak NT for penalty". Yes, we didn't get run over often - and we didn't get nailed opposite no game nearly at all - but frequently the best result you are going to get after 1NT weak by opps is whatever they run to doubled; okay, you have a game on, and defending is going to net either just under or just over your game score, but you have to *find* the game starting at the 2 level, when the rest of the field get to show a good hand with a cuebid advance *at the two level* (1D-1S-p-2D vs 1NT-2S-p-?) And if you play double not for penalty, well I've been known to pass (to play) with nothing and hope it doesn't get converted (it rarely does), where I would have run against a penalty double (or a no-comment pass, even).

(I like "pass is to play" runouts for several reasons, but mostly because I'll trade some safety in finding a place to land (more sequences with pass forces XX) for punching the preempt - so, LHO, you'd better guess right, because if you pass, your next choice is what to play to the opening lead. If you bid, of course, you've let us off the hook, and you don't get to know what kind of hand I have. Have fun! Of course, 1NT-X-XX- puts a *lot* of pressure on fourth hand when it's natural - a lot more, I believe, than 1NT-X-p-p; XX-p-p-.)

I gravitate toward limited opening, weak NT systems with aggressive preempts, because of the number and frequency of "pd, don't worry about what I have, pass this" bids I get to play. End-the-partscore-fight bids work best when there's enough ambiguity that it really is unsafe not to end the partscore fight; weak 1NT - and "to play" responses to it - do that well. Yes, we lose on the roundabouts; but if you make 'em guess, and guess early, they *will* guess wrong sometimes.

Michael.

[hotShot]

Stephen Tu, on Apr 13 2005, 07:58 PM, said:

hotshot wrote:

Quote

You will make 1NT+ 65% of the time. If opps double and you run, there is a suit 80% of the time, that lets you take 8 or more tricks.

Eh? This can't possibly be right. I don't think you are interpreting the statistics properly. Didn't your simulation determine that the opening side can take 8+ tricks somewhere ~80% of the time? *But that includes large number of hands where they don't double you*. A lot of these hands were ones where your side just bids uncontested to your partial or game. When 2nd hand does have a double, the percentage of success of both 1nt or a runout is going to drop drastically. Run the numbers again given a 1st seat 12-14 NT opener, and 2nd seat 15+. Use a larger # of boards, also.

I like the weak NT. You don't get penalized that often, and the opponents get themselves in trouble probably more often than they get you. But if you are doubled, you are often in trouble. There's no way you have a successful runout 80% of the time. The opponents will often let you off the hook when you run, but that's their error, not that the runout would have been successful.

You might make at least 2 of a suit 80% of the time overall, but not 80% of the time after they double.

Did you consider that many people use dbl at 1rst seat not as penalty, but to show a one suited hand or a 2 suited hand with spades (e.g.Lionel).
A dbl can also appear in 4th seat, often as reopening.

Of cause a second seat penalty dbl, lowers the chance.

I'm still increasing the number of boards, but the simulation needs half an hour for 100 boards.

[luke warm]

Winstonm, on Apr 13 2005, 12:24 PM, said:

Second, a disadvantage of the weak NT no one talks about is having to open the 15-17 NT with a minor.

i don't find this a problem at all...

[Winstonm]

Quote

Luke Warm: i don't find this a problem at all...

I don't find it a problem either. But I do see it as a disadvantage. However, there can also be an advantage if you play as some do that if the auction starts 1D-1H-2H then else opener is unbalanced or holds an opening NT.

All a matter of perspective and what words mean, eh?

WinstonM