[VixTD]

Consider the following two auctions:

(1)

---

(2)

---

Traditionally, auction (1) was considered non-forcing, but encouraging, and (2) was forcing for one round (Eric Crowhurst, Precision Bidding in Acol, 1974). By the year 2000 even Crowhurst (The Acol Index) had changed his mind and both these sequences were regarded as forcing. This view is corroborated by Albert Dormer (The New Complete Book of Bridge, 1996), although both these later works suggest that responder's reverse need not show more than about 10 hcp, so presumably a minimum bid by opener could be passed.

If both these sequences show hands of about the same strength, is the concept of "responder's reverse" now obsolete? Does anyone play it as showing extra values and game-forcing? What prompted the question was the following hand which a friend bid to 6♦ using a strong club while their Acol opponents stopped in 3NT.

---

Should 3♦ over 2NT be forcing? How else can EW investigate slam below 3NT?

[PhilKing]

Whether or not you play 2♠ in sequence two as F1 or FG, a reverse followed by 3♦ should be game forcing.

[Zelandakh]

In traditional Acol, #1 was non-forcing and #2 was F1R. In EBU Modern Acol, #1 is F1R and #2 is GF. As Phil points out, even if #2 is not immediately GF, a 3♦ bid on the third round certainly would be.

[VixTD]

Zelandakh, on 2013-November-04, 09:03, said:

In EBU Modern Acol, #1 is F1R and #2 is GF.

I must admit I was surprised to find out that it isn't GF, at least according to my more modern sources.

My friend has sent me this hand from a work by Squire in 1957 in which he argues the 3♣ bid has to be forcing, just proving that the concept has actually been around for a long time:

---

I agree it doesn't make sense for 3♦ in the first auction, and 3♣ in the second, to be non-forcing, but I play in many partnerships in which I wouldn't dare make such a bid for fear of partner passing.

[FrancesHinden]

What Phil said. Even if you don't play responder's reverse as game forcing, certain when you bid 3D on the next round that's forcing.
Opener can't actually have 4 spades on the second sequence, so you aren't bidding 2S to find a spade fit, you are bidding it to describe your hand and set up a forcing auction. If you just wanted to invite in diamonds, you could bid 3D.

The non-reverse auction is murkier, because a heart fit is still a possibility if opener didn't have enough to reverse.

The other problem with your auction on the diamond hand is opener's 2NT bid. If he thought it was non-forcing, it's an underbid. It's also a misbid with Axx in clubs and a 7th diamond.