As my friend Marty Bergen says, he advises students to pray that reverses don't come up.
Basically, a "reverse" is when opener's rebid (2nd bid of the auction) meets both A & B:
A) Opener's rebid is in a HIGHER ranking suit than his first suit
B) Opener's rebid is at a HIGHER level than responder's response (but never a jump!)
Just those two simple lines are enough to make many of my students' eyes glaze over.
So, these are reverses:
In all auctions above, the last bid is made by the opener, of course. Each bid is natural and promises extra values (approximately 17-20 counting useful distribution). Reverses are forcing one round--the responder can not pass. However, reverses are not forcing to game. Opener's jumpshift (a different topic), is game forcing.
Contrast these two auctions:
as opposed to
On the first auction, opener (who jumped and changed suit) has to have 19+ -- his jump-shift is natural and game forcing.
On the second auction, opener (who reversed) has to have 17-20 -- his reverse shows extra values, is forcing one round, but not forcing to game. (Note: Never Jump and Reverse -- such as 1-1-3. There is no need to make such a bid, because 2 shows up to 20 -- you can't have more than 20.)
All reverses should show unbalanced hands. With balanced hands, the opening is 1NT or 2NT, or the rebid is 1NT or 2NT. Reverses show that the first-bid suit is longer than the suit reversed into. So, 1-1-2 would show not only 16/17+, but would indicate 5+ and 4.
After Opener's Reverse:
As to the follow-ups, after, say 1-1-2, I recommend:
2= 5+ spades, 1-round force
2NT=Forcing, but could be a weak hand (responder can pass opener's next bid). Denies 5+
3=Natural, GF (some decent values)
3=Natural, GF 4 hearts
3=Natural, good suit, GF
3NT=Natural, some extras, but no real slam interest.
The generic summary of the above treatment would be as follows:
After opener's reverse,Responder's repeat of his suit=5+, one-round force
2NT=Potentially a weak sign-off type of hand
I don't advocate "reverses" after a 2/1 auction -- so there is no such thing as opener promising extras (1-2-2 can be bid with a dead minimum). I prefer to think of reverses only when the auction starts 1-1 (any 1 opening and any 1-level response, including 1NT).
Reverses after negative doubles are a tricky topic. For example, is this a reverse?
This, and other similar auctions have confounded bridge players and teachers for decades. If I had the perfect answer for you, I'd tell you--but I don't. My best suggestion is to consider these auctions as not promising extras. Certainly, if North's rebid was 2 (the suit that South surely has), it wouldn't be considered a reverse showing extras.
If you're a new player, be prepared to struggle with the concept of reverses. Unfortunately, though, they are part of the game. I've heard: "I don't play reverses." That is not acceptable. It is like saying: "I don't play rebids by opener."
Here are 4 Practice Deals:
1 A Switch in Time
2 Where I Live
3 And One For Me
4 As Long as They Aren't 5-1
What Should we Play
Last update: June 2014