after 1NT opening by RHO I overcalled 2H with about 12 pts . LHO passed and partner responded 3D . Opener passed as did I since I assumed he was just showing a better D suit than my H . In fact partner was strong and actually should have supported my H with 3 of his own . If opener had bid a suit rather than 1NT then partner could have made an unassuming cue bid in that that suit to show strenghth and I would have bid on . My question which I would appreciate views on is then - how does responder show strength when partner has overcalled over a 1NT opening ?
When opponents have bid NT and you have no suit to cue bid there is a problem. One way to solve it is to play that when partner has overcalled with 2H or 2S natural then 2NT is a try for game rather as people play in response to a Weak Two opening. I think this is better but would not spring it on someone without discussion. I would also play 3D as forcing and if I had long diamonds and not much then I would not fight partner. He will often have 6 cards for his overcall. If you get doubled for penalties in 2H then with a string of diamonds you can reassess.