[Liversidge]

We play Acol & weak No Trump.
My references state that to make a reverse you need 16+ points (some say 15+). Thy don't diffeentiate between a reverse after a 1-level response and a reverse after a 2 level response.
After 1C-1H-2D, a weak responder (6 HCP) might have to show preference at the 3 level and if opener has a 12 point hand would take the auction too high unless opener has 16 HCP, giving the partnership a combined 22 HCP. But after 1D-2C-2H, responder has shown at least 9 HCP, so why can't opener make the reverse bid with 13 HCP, a combined 22+ HCP? Why do my references (Brunner, Klinger etc) make no differention? I presume I am missing something obvious.

[Stephen Tu]

After a 1 level response, you only need usual 3 level safety opposite a minimum response, because you have mechanisms for responder to show a weak hand and sign off in 3m or whatever.

After a 2/1 response, you still want extras, because now you want your reverses to be forcing to game. If you play that the reverse can be minimum, then responder with a good hand now has to do a lot of jumping or awkward 4th suit forcing calls, or use 2nt artificially, and with the reverse already tending to consume a lot of space it makes things very awkward. After 2/1 you want to cater to game/slam hands which are a lot more valuable than partial hands and come up more often after 2/1 than after 1/1. Also with a minimum there's no overwhelming reason opener needs to show a 2nd suit right away; if there is a fit there responder will bid it.

If you are playing 2/1 GF as opposed to Acol, with the 2/1 FG to begin with, it's more feasible to play certain 2 level reverses on minimums. Some also play high reverse as minimum (e.g. 1s-2h-3c), but IMO that's not really best and leads to a lot of guessing as to ranges.

[P_Marlowe]

Liversidge, on 2019-February-12, 03:21, said:

We play Acol & weak No Trump.
My references state that to make a reverse you need 16+ points (some say 15+). Thy don't diffeentiate between a reverse after a 1-level response and a reverse after a 2 level response.
After 1C-1H-2D, a weak responder (6 HCP) might have to show preference at the 3 level and if opener has a 12 point hand would take the auction too high unless opener has 16 HCP, giving the partnership a combined 22 HCP. But after 1D-2C-2H, responder has shown at least 9 HCP, so why can't opener make the reverse bid with 13 HCP, a combined 22+ HCP? Why do my references (Brunner, Klinger etc) make no differention? I presume I am missing something obvious.

After a 2/1 response a reverse should create a game forcing auction.
If you respond light at the 2 level this increases the requirement on the strength of the hand
making the reverse.
If the 2/1 response is already game forcing, than there is a debate, if you need add. strength
or not, I belong to the camp, that says yes, but this is a different topic.

[Liversidge]

Stephen Tu, on 2019-February-12, 03:52, said:

After a 1 level response, you only need usual 3 level safety opposite a minimum response, because you have mechanisms for responder to show a weak hand and sign off in 3m or whatever.

After a 2/1 response, you still want extras, because now you want your reverses to be forcing to game. If you play that the reverse can be minimum, then responder with a good hand now has to do a lot of jumping or awkward 4th suit forcing calls, or use 2nt artificially, and with the reverse already tending to consume a lot of space it makes things very awkward. After 2/1 you want to cater to game/slam hands which are a lot more valuable than partial hands and come up more often after 2/1 than after 1/1. Also with a minimum there's no overwhelming reason opener needs to show a 2nd suit right away; if there is a fit there responder will bid it.

If you are playing 2/1 GF as opposed to Acol, with the 2/1 FG to begin with, it's more feasible to play certain 2 level reverses on minimums. Some also play high reverse as minimum (e.g. 1s-2h-3c), but IMO that's not really best and leads to a lot of guessing as to ranges.

QED!

[Liversidge]

P_Marlowe, on 2019-February-12, 03:54, said:

After a 2/1 response a reverse should create a game forcing auction.
If you respond light at the 2 level this increases the requirement on the strength of the hand
making the reverse.
If the 2/1 response is already game forcing, than there is a debate, if you need add. strength
or not, I belong to the camp, that says yes, but this is a different topic.

I think (?) that in Acol a reverse at the 2 level after a 2/1 response is only forcing for one round. A reverse at the 3 level (e.g 1♠-2♦-3♣) is game forcing.

[Cyberyeti]

Liversidge, on 2019-February-12, 04:37, said:

I think (?) that in Acol a reverse at the 2 level after a 2/1 response is only forcing for one round. A reverse at the 3 level (e.g 1♠-2♦-3♣) is game forcing.

In very old style Acol, where 2/1 only required an 8 count that may have been the case, nowadays people usually require a bit more so 1♦-2♣-2♥ can be FG as you're guaranteeing the values for game.

[pescetom]

P_Marlowe, on 2019-February-12, 03:54, said:

If the 2/1 response is already game forcing, than there is a debate, if you need add. strength
or not, I belong to the camp, that says yes, but this is a different topic.

I wasn't aware that there was a camp that says 1♠ 2♥ 3♣ needs no additional strength whatsoever, but if there is then I'm in an intermediate camp: it needs a better than minimum opening, but not natural reverse strength, just enough to allow partner without a major fit to decide whether or not to risk going beyond 3NT.
Not to be confused with the situation 1♥ 2♣ 2♠ which requires no additional strength at all.

[steve2005]

Precision bidding in Acol by Crowhurst suggests 17 hcp or I presume equivalent in distribution for a reverse

[helene_t]

This is an unpopular opinion, but I don't see any logical reason why
1♦-1♠
2♥
should require fewer combined points between the two hands than
1♦-2♣
2♥

They take up the same amount of bidding space. Of course, on the second auction, responder has a problem with six clubs and GF values if 3♣ is not forcing, but OTOH the fourth suit is cheaper.

But maybe it is just easier to remember that a reverse shows 16+ regardless of what responder has shown.

[Tramticket]

Liversidge, on 2019-February-12, 03:21, said:

After 1C-1H-2D, a weak responder (6 HCP) might have to show preference at the 3 level and if opener has a 12 point hand would take the auction too high unless opener has 16 HCP, giving the partnership a combined 22 HCP. But after 1D-2C-2H, responder has shown at least 9 HCP, so why can't opener make the reverse bid with 13 HCP,

I also play Acol, weak NT.

I like to keep reverses up to strength. It greatly simplifies subsequent bidding. I like to have 17+ HCPs for a reverse over a one-level response, but I might reverse with a particularly good 16 (good shape / intermediaries / points working in long suits etc.). After a two-over-one response, you need a reverse to create a game forcing auction - this means 15+ HCPs opposite a modern Acol standard of 10 HCP (or a good 9) two-over-one.

So you are partly right, the values needed to reverse should differ. But I strongly recommend increasing both!

[Stephen Tu]

helene_t, on 2019-February-12, 22:24, said:

This is an unpopular opinion, but I don't see any logical reason why
1♦-1♠
2♥
should require fewer combined points between the two hands than
1♦-2♣
2♥

They take up the same amount of bidding space.

On the first auction, you reverse on strong hands of the appropriate shape because you kind of have to. Lower bids are underbids and non-forcing, you fear missing game and not describing your hand correctly. The 2H is the lowest forcing bid.
On the second auction, if you have a minimum, 2♦ is more economical than 2♥. The 2♥ auction is a bit more manageable because of the cheap 4th suit, but reversing into 2♠ is far worse. Why cramp your own auction, what's the *gain* from reversing on a minimum?

[helene_t]

Stephen Tu, on 2019-February-13, 05:47, said:

What's the *gain* from reversing on a minimum?

You would know that the 2♦ rebid (which is non-forcing in Acol) shows 6.

But OK, if responder passes the 2♦ rebid he won't have four hearts anyway as he would have bid 1♥ instead of 2♣ with 9 points and 4-5 in rounded suits.

So I suppose it was a silly idea. Thanks