I've gradually (based on reading and more learning, and based on an apocryphal bit of philosophy from Zia) increased the frequency of opening 1 NT hands with semi balanced (15-17) hands including sometimes with 5-card majors, and sometimes with an upgraded 14 or downgraded 18, similarly with 2NT (upgrade or downgrade by a point occasionally). I must admit I dont really have any feel for which hands with a 5 card major (or minor) are best opened 1NT or 1m or 1M and tend to use a bit of feel on the shape and stops. However I've also learned not to care too much about having stops in all 4 suits which used to lead me to prefer suit openings. Note this discussion is for 5-card major systems. I think about things differently playing Acol with weak NT.
So what are the considerations.
I know the usually valid shapes for 1 NT are 4333 5422(???? two doubletons dodgy and should never be bid?) 5332 4432, in any order. I hardly ever open with singletons although have occasionally started doing it with an Ace singleton (and maybe a King but doubtful)
But is it usually regarded as acceptable and safe practice to open any of those shapes irrespective of distribution of HCPs or are there pointers towards when you should open a suit.
What are the pros and cons. I know 1NT is good for hiding lead options from defence, gives a point count, is preemptive, no trumps may score better at MPs, a no trump game may often be easier (1/2 fewer tricks) but are there any downsides such as the risk of missing a good 5-3 or 5-4 fit. I know they usually will make many tricks in NT too but there is the risk of a bad 2-2 fit in one of the suits.
How do the percentages work out. Does it matter between IMPs and MPs
regards P
Note Just now I opened one (5332, 5cm) with a worthless heart doubleton and unfortunately partner had a doubleton and no stop, and had an unlucky lead, down 3, they cashed 7 defensive tricks. Didnt score too badly in the IMPs game I was in since the alternative was opps getting a minor part score but ...... its still a big swing in a team game.However having just kibitzed a team game they dont always seem to care about wild swings sometimes
