After reading and trying to take in all this discussion it seems to me that the essence is answering the questions:
1. What should 4th suit forcing mean?
2. How should you respond to a 4th suit bid?
The issues have prompted me into examining whether or not my present methods could be improved. That is why I have put "should" in the questions.
1. I have no idea what the beginners class says. However, I firmly believe that a 4th suit forcing bid should be saying to partner "Please tell me more" More fully: "I cannot make a bid that accurately gets over to you what you might need to know, so I will make a waiting bid. All I am telling you is that I have the strength to take the bidding to ...." If an unfamiliar partner (normally Acol style) asks me what level I would like a 4th suit bid at the 2-level to force to, I will say 2NT. I am not sure that this is best, but that is another story.
2. I don't think that as partner of the 4th suit bidder, you must bid no trumps if you have a stopper. After all if you were 6160 with the singleton
♥Ace it would be ridiculous to bid no trumps. The question is: "How distributional does your hand have to be before distribution takes priority in your response?" If the bid is forcing to 2NT, then I think that any distributional feature you haven't already mentioned should take priority. In the example sequence 1
♠ 2
♣, 2
♦ 2
♥, I take Opener as showing at least 5
♠4
♦, so after 2
♥, I take:
2
♠ = 6 spades
3
♣= 3 clubs (therefore 5143)
3
♦ = 5 diamonds (therefore 55)
3
♥ = 4 hearts (therefore 5440)
I notice with interest the fairly popular treatment of 3
♥ to mean "I have half a stop"
Then we come to 5242 or even 5341 without a heart stop. Clearly, you have no more to say within these defined rules. So a lie has to be told. Judgement has to be used as to which is the least potentially damaging lie. Before I get to that point, I ask myself the question; "If 2
♥ is a game force, does this change things?" Well I suppose it could do, if you decided that your first duty was to show a stop and leave additional distribution until later. But that method is foreign to me , so I will listen and learn.
Anyway, back to the example. With
♥Q8 my vote was narrowly in favour of 2NT with 3
♣ as second choice. Suppose pd had
♠A5,
♥752
♦972,
♣AKQ97. Well, 3NT and 4
♠ are hopeful and 5
♣ is reasonable. So I would have to make my excuses if pd raises to 3NT and opps take the first 5 tricks and the diamond finesse is right. However, if my hand was
♠K974,
♥108,
♦AKJ2,
♣J9, then I would definitely bid 3
♣. It seems to me that with nothing more to say, the bid that is least likely to get you into trouble is 3
♣. So I believe that if your spades are not good enough to play in game opposite
♠Ax, Kx or Qx in a 5-2 fit, then you should bid 3
♣ on any doubleton. If your shape is 5341 with 3 small hearts and poorish spades, then I would risk a bid of 2NT.
Side issues:
1. If the rules and ethics authorities want my partner to alert my bid of 2NT knowing that I might not have a normally defined stop, I am sure she would be happy to comply.
2 I think that I agree with Helene, that 2NT should show 12-14 or 18-19 and 3NT 15-17. The principle of slower arrival shoing strenth should only apply with suit support sequences.
3. 1S 2C, 2D 2H, 2NT 3H I would take as showing 5 hearts and therefore 6 clubs. If you have any other way of showing this distribution, then I suppose you could use 3H (The Whereagles way) as saying "Are you kidding me with 2NT or not?"
Phew