[barmar]

ArtK78, on 2013-October-01, 06:29, said:

The comment was made that 10-12 1NT openings work well against weak opponents.

Anything works well against weak opponents, so that comment really doesn't add anything.

True, but some things work especially well against them.

Maybe it's intermediate players, who think they're good, that are most screwed up by it. They know that in general you should balance aggressively, but haven't yet learned that this can be extremely dangerous over mini1NT-P-P because responder can pass with many good hands.

[ArtK78]

barmar, on 2013-October-01, 09:22, said:

True, but some things work especially well against them.

Maybe it's intermediate players, who think they're good, that are most screwed up by it. They know that in general you should balance aggressively, but haven't yet learned that this can be extremely dangerous over mini1NT-P-P because responder can pass with many good hands.

As I mentioned earlier, I have been using the 10-12 1NT for about 25 years. There was an event quite some time ago where it (and everything else) worked extremely well, especially against the top pairs.

I was playing in a Flight "A" pair event on a Saturday at a regional in Cherry Hill, NJ. This was before there were 20 events being conducted simultaneously, so all of the top players were in the event.

At the end of the afternoon session, my partner and I scored about 90% on the last 6 boards to bring us back to slightly above average. A recap sheet was posted listing the top 60 pairs in event after the afternoon session. We did not make the list.

In the evening session, everything we did worked, and our opponents were making mistake after mistake. We had numerous opportunities to open the 10-12 1NT, and every time that we did, we either stole the board or our opponents got themselves into trouble. This was especially true of the top pairs in the event that we faced in the evening session.

On the last board of the evening session, our opps bid up to 7NT which required a guess for a queen in an eight card fit. Needless to say, declarer got it wrong. Shortly after the round was over, but before the results were posted, the DIC looked up at us and said "Congratulations!" We had scored about 74% for the evening session and won the event by over a board.

There have been a number of other situations where our mini NT has resulted in very good results, and a few where it did not. But, in my experience, it has been far more good than bad. And I will never forget that one session where everything worked out in our favor.

{By the way, that event was the middle event of 3 consecutive regional victories at that tournament - the morning KO, which ended Saturday morning, the Flight "A" pairs on Saturday, and the Flight "A" Swiss Teams on Sunday - three regional wins in a 36 hour time span).

[mycroft]

I play it in the context of a Precision system first 3 seats NV (and there are problems with that as well - where do you put your bad 16 balanced? What do you do when partner's shown good 16-19?), and yes, you give away on defence, whether you open 1NT or pass, as well as being able to use it by third-hand. You need to change your system opposite a passed hand to not have calls that cater to partner being 10-bad 12 balanced.

But I am impressed at how effective it is, even at A level, which around here means a couple of GrandLMs, a couple of 10K but no open win, a couple of open win but not 10K, and a few people who expect they can beat the above on a good day, as well as the normal strong players and point-accumulators. Sure, we lose to the best frequently, but we do that playing standard, too. At least if we give them different problems to the field, they may have no answer.

It's not for the faint of heart, and it's not for the players that won't work on their runouts, and it's not for the players who can't bull out a hopeless contract for the best possible result (sometimes it's a great result, if you don't panic!)

[TylerE]

mycroft, on 2013-October-01, 10:42, said:

I play it in the context of a Precision system first 3 seats NV (and there are problems with that as well - where do you put your bad 16 balanced? What do you do when partner's shown good 16-19?), and yes, you give away on defence, whether you open 1NT or pass, as well as being able to use it by third-hand. You need to change your system opposite a passed hand to not have calls that cater to partner being 10-bad 12 balanced.

Simple, we open all 16's 1♣, period. There is no such thing as a "Bad 16 opened 1♦".

We also make the sequences

1♣ - 1♠ (Balanced hand)
1NT (Semi-forced, denies extreme shape or extras) - stayman/transfer
response - 2NT show 8-9 and is NF. This provides an escape valve to stay out of game on bad 16 opp bad 8.

[fromageGB]

Years ago I played 10-12 for a few years at matchpoints in a standard 5 card major system, and it was not good. One reason, as mentioned, is that we had no way to avoid large range rebids of NT. However, there are downsides to having both 1♣ and 1♦ followed by 1NT as different ranges, because that impinges upon your otherwise useful meanings for these. Another reason was that it is too premptive, and when partner has a hand it gets in the way, preempting him.

Delighted to drop it in favour of a 15/16 1NT.