[Zelandakh]

 fromageGB, on 2019-November-05, 05:21, said:

Precisely. A 5 card suit has more likelihood of finding 3+ cards opposite than fewer, the suit contract makes one more trick than NT, and at matchpoints the score of 110 is vastly superior to the score of 90. Similarly 140 rather than 120. Depending on the field, you can get a significantly better percentage.

Is this potential advantage not completely swallowed by the combination of being forced to play in a 5-2 fit, often making the same number of tricks as those in NT, combined with the times when opps are able to find their own fit, which they would have missed after a 1NT opening, particularly their finding 2♠ after a 1♥ opening?

[pescetom]

 Zelandakh, on 2019-October-30, 04:10, said:

There is some very good statistical analysis online that suggests opening 1NT with 5♥(332) is a winner whereas opening 1NT with 5♠(332) is a loser.

 fromageGB, on 2019-November-05, 05:21, said:

If anyone is quoting analysis that demonstrates the supposed superiority of the 1NT open, I would be interested in whether the data basis is teams or not. This seems probable, and of course the conclusion is therefore not valid at matchpoints.

I couldn't find any such analysis online, maybe Zelandakh can help. I did find a mention that Richard Pavlicek had done such analysis and concluded that opening 1NT was a clear winner with 5 hearts and a slight loser with 5 spades (no indication about scoring system or other assumptions). I can't find that on the RP site, although I did find this sobering 1NT vs 2S comparison instead.

[pescetom]

 Zelandakh, on 2019-November-05, 06:48, said:

Is this potential advantage not completely swallowed by the combination of being forced to play in a 5-2 fit, often making the same number of tricks as those in NT, combined with the times when opps are able to find their own fit, which they would have missed after a 1NT opening, particularly their finding 2♠ after a 1♥ opening?

I would have thought partly so. There is also the point that opps (wisely or not) will often not leave us in 1NT. And also that 1NT might lead to a hearts fit that would not have been discovered over 1S. But above all, what I do not miss is the 1S - 1NT - 2NT auction where we were basically guessing and quite likely to go down or miss game.

[fromageGB]

 pescetom, on 2019-November-05, 07:51, said:

I did find a mention that Richard Pavlicek had done such analysis and concluded that opening 1NT was a clear winner with 5 hearts and a slight loser with 5 spades (no indication about scoring system or other assumptions). I can't find that on the RP site, although I did find this sobering 1NT vs 2S comparison instead.

This analysis (or my analysis of this analysis) is amazing. If my sums are right opening 1NT is a massive loser.

First what I read a single line to say - eg the top line - is that with the given distribution, 1NT wins (ie is the better open) and 2♠ goes off 19.54 percent of 30302 cases, while 2♠ makes on 42.94%+37.52% of 30202. Agreed? The website says that the figures are for where there are no overtricks in either contract.
Now assuming the shape you are concerned with in the choice of whether to open 1NT or 1♠ is the 5{332} and you don't open 1NT on more extreme shapes, you can eliminate those other shapes.
Multiply each percentage by the number of cases to give the effective frequency result, add the columns, and you get a total of 1NT winning on 8.7% of hands and 2♠ winning on 91.3% of hands.

That's a huge difference in a matchpoint scenario. I can't believe it would be that different for a 1♥ open, as the play is the same, but of course opponents could intervene with a 1♠ bid.

[fromageGB]

 Zelandakh, on 2019-November-05, 06:48, said:

Is this potential advantage not completely swallowed by the combination of being forced to play in a 5-2 fit, often making the same number of tricks as those in NT, combined with the times when opps are able to find their own fit, which they would have missed after a 1NT opening, particularly their finding 2♠ after a 1♥ opening?

Not in my pairs experience. Spades are obviously better than hearts, but if the opponents overcall a major they are likely to be overcalling or protecting a 1NT. In teams, opponents are more cautious at partscores. Yes, you do get the 5-2 fit but this often plays for a trick more too. Why else would everyone transfer in response to a 1NT open?

[fromageGB]

 pescetom, on 2019-November-05, 08:02, said:

...But above all, what I do not miss is the 1S - 1NT - 2NT auction where we were basically guessing and quite likely to go down or miss game.

Of course any contract is a guess when you do not have the strength to do much bidding, but missing game is a bit drastic. Would a 15 hcp Gazzilli help here? If you are thinking of the 15/16 opener and an 8-10 responder, the bidding would not be your 1♠ 1NT 2NT but 1♠ 1NT 2♣ 2♦ 2NT and responder is better placed to bid game.

EDIT : and if responder had a 6/7 count the bidding would likely go 1♠ 1NT 2♣ 2♠.

[pescetom]

 fromageGB, on 2019-November-06, 07:40, said:

Of course any contract is a guess when you do not have the strength to do much bidding, but missing game is a bit drastic. Would a 15 hcp Gazzilli help here? If you are thinking of the 15/16 opener and an 8-10 responder, the bidding would not be your 1♠ 1NT 2NT but 1♠ 1NT 2♣ 2♦ 2NT and responder is better placed to bid game.

EDIT : and if responder had a 6/7 count the bidding would likely go 1♠ 1NT 2♣ 2♠.

Yes, if we were still opening that hand 1S then Gazzilli or some other 2♣ convention would certainly be an improvement.
As it is, I'm quite happy opening 1NT for now. The "rest of room happily in 2M and us stuck in 1NT" nightmare MP scenario just doesn't seem to happen often, for one reason or another, whereas we often get a better score from things like rightsiding the NT contract, accurante quantitative bidding, inferences from systematic opening of 5cM as 1NT both after 1M and after 1NT, the neat way this ties in with our stealthy Stayman and well defined transfers to put opener in the driving seat when appropriate and to hide his hand.