With the introduction of the Acol Bidding System, bridge players have been trying to modify, modernize, and update it. The following is a short summary of a modification by Mr. George Jesner, born in Scotland in 1925, and who then took up residence in Canberra, Australia. Mr. George Jesner, bridge teacher, instructor, writer and columnist, was a member of the Scottish team, which won the Camrose in 1964. He wife of many years is Dorothy, also a worthy bridge player and bridge opponent at the table.

He was President of the Australian Bridge Federation and later served as the Public Officer for the Australian Bridge Federation. He was also a columnist for the Australian publication Australian. In the year 2005 he celebrated his 80th birthday at the bridge club in Canberra, Australia.

Any additional information would be greatly appreciated as well as any additional contribution to the person of Mr. George Jesner.

The attempt has been made to present this information as accurately as possible as devised by Mr. George Jesner. The formatting may be somewhat different as opposed to a more modern presentation, but the visitor will certainly discover the content in the manner presented on this web page.

There will be a certain terminology used, which will not be understood by every bridge player. We have attempted to include the clarifications as much as possible. The Acol System proposed and offered by Mr. George Jesner is comprehensive, and we hope that we have given this modification due credit. After reviewing the material contained on this page, the bridge player could have questions which we have not anticipated. If this is the case, please contact us.

As an introduction and explanation, this modification, which is quite involved, by Mr. George Jesner is a natural system featuring 4-card suit openings, a Weak No Trump with a range of 12 to 14 high card points, and Benjamin Two-Bids. Be aware that we have tried to include most of the material and that it is quite long.

Opening Bids

Opening   Meaning
1 club:   10-21 high card points. At least 4 Clubs.
1 diamond:   10-21 high card points. At least 4 Diamonds.
1 heart:   10-21 high card points. At least 4 Hearts.
1 spade:   10-21 high card points. At least 4 Spades.
1 NT:   12-14 high card points. Any distribution of 5-3-3-2, 4-3-3-3, 4-4-3-2 (including weak 5-card Majors).
2 club:   8+ Quick Tricks in an unspecified suit, or 21-22 high card points, or 25-26 high card points with a balanced hand.
2 diamond:   Game Forcing hand, or 23-24 high card points, or 27-28 high card points with a balanced hand.
2 heart:   4-9 high card points. A 6-card Heart suit.
2 spade:   4-9 high card points. A 6-card Spade suit.
2 NT:   19-20 high card points. Balanced hand.
3 club/3 diamond/3 heart/3 spade:   Standard preempts.
3 NT:   Broken preempt in either Minor.
4 club:   Transfer to 4 Hearts.
4 diamond:   Transfer to 4 Spades.
4 heart:   Standard Four Level preempt.
4 spade:   Standard Four Level preempt.
4 NT:   Specific Ace asking bid.
5 club/5 diamond:   Standard preempt.
5 heart/5 spade:   Specific trump asking bid.
Raise to 6 with one top honor.
Raise to 7 with two top honors.
6 club/6 diamond/6 heart/6 spade:   Specific trump asking bid.
Raise to 7 with one top honor.
     

One Level Opening Bids
Open the longest suit. If two suits of equal length (whether 4/4 or 5/5) open the higher ranking, which includes touching suits, except with Clubs and Spades where the opening should be 1 Club. With 4-4-4-1 distribution, open the suit below the singleton.

Therefore, in the bidding auction: Opener: 1 diamond - Responder: 1 heart - Opener: 1 spade, the 1 Spade rebid by the opener shows a distribution of 5 Diamonds and 4 Spades.

There are occasions where a 4-card suit is opened in preference to a 5-card suit. For example, open 1 Spade in preference to 1 Heart when holding a good 4-card Spade suit and a very poor 5-card Heart suit, and less than 16 points. It avoids a rebid problem with a poor 5-card suit and insufficient values to reverse on the second round. The suit must be very poor, otherwise the

Opener   Responder   Meaning
1 spade   2 spade   May show a 3-card support.
4 heart   Gives responder the choice of game;
Shows 5 Hearts, quality is as good as Spade holding.
1 heart   2 heart
2 NT   17-18 high card points

Raises of One Level Opening Bids

Opener   Responder   Meaning
1 club   3 club   Limit Raise
1 diamond   3 diamond   Limit Raise
         
1 heart   3 heart   Limit Raise.
3 No Trump cues the Ace of Hearts.
1 spade   3 spade   Limit Raise.
3 No Trump cues the Ace of Spades
         
1 club   4 club   Gerber
1 diamond   4 diamond   Distribution: 3-3-4-3.
Strong holding. Attempting Slam.
3 No Trump has been bypassed.
         
1 heart   4 diamond   13-14 high card points. Distribution: 3-4-3-3.
Shows a poor hand lacking intermediates.
Example: Axx - Qxxx - Kxx - KJx
No ruffing values.
         
1 spade   4 diamond   13-14 high card points. Distribution: 4-3-3-3.
Shows a poor hand lacking intermediates.
Example: Qxxx - Axx - Kxx - KJx
No ruffing values.

No Trump Responses to One Level Opening Bids

Opener   Responder   Meaning
1 club   1 NT   7-9 high card points. In principle, it denies 4 Hearts or 4 Spades.
1 diamond   1 NT   6-9 high card points. In principle, it denies 4 Hearts or 4 Spades.
1 heart   1 NT   5-9 high card points. In principle, it denies 3-card Heart support, otherwise responder raises to 2 Hearts and also denies 4 Spades.
1 spade   1 NT   5-9 high card points. It denies 3-card Spade support, otherwise responder raises to 2 Spades.
1 Any Suit   2 NT   Shows 10-12 high card points and is a natural bid, and denies both 4-card Major suits, except over 1 Spade where responder may have 4-card Heart suit. This bid also shows at least a doubleton in partner's suit, but the responder may have a 3-card support for opener's Major suit, but this bid denies a 4-card support for opener's Major suit.
1 Any Suit   3 NT   Shows 13-14 high card points, and is a natural bid, and denies both 4-card Major suits, except over 1 Spade where responder may have 4-card Heart suit. This bid also shows at least a doubleton in partner's suit. Responder may have a 3-card support for opener's Major suit, but this bid denies a 4-card support for opener's Major suit.

Note that the chance of opener holding 4 Spades after opening 1 Heart are minimized.

Suit Responses to One Level Opening Bids

Jump Shifts show 15 high card points plus, and at least a 4-card suit, but the Jump Shift says nothing about the suit quality, and Jump Shifts are also Game Forcing. With a 4-card plus support for opener's suit, the Jump Shift may be a short suit, called a Stepping Stone. This means bidding the suit with the highest control. For example: with Axx and KQx, the correct bid is to bid the suit containing the Ace.

Balanced Hand Openings

12-14 high card points: 1 No Trump
15-16 high card points: 1 suit and rebid lowest No Trump
17-18 high card points: 1 suit and Jump rebid in No Trump (usually 2NT)
19-20 high card points: 2 No Trump
21-22 high card points: 2 Clubs and rebid 2 No Trump over 2 Diamonds negative
23-24 high card points: 2 Diamonds and rebid 2 No Trump over 2 Hearts negative
26-26 high card points: 2 Clubs and rebid 3 No Trump over 2 Diamonds negative
27-28 high card points: 2 Diamonds and rebid 3 No Trump over 2 Hearts negative

Example

Opener   Responder   Meaning
1 spade   2 club
2 NT   15-16 high card points
3 NT   17-18 high card points

1 No Trump Opening Bid

1 No Trump shows 12-14 high card points and may contain a 5-card Minor or a weak 5-card Major.
This Guideline helps to avoid rebidding the weak Major suit.

Responses

Opener   Responder   Meaning
1 NT   2 club   Stayman. Bidding 2 Hearts would show both Major suits.
  2 diamond/2 heart/2 spade   Natural sign-offs.
  2 NT   Baron - an explanation of the Baron System. Game Forcing. Suggesting Slam.
  3 club/3 diamond/3 heart/3 spade   These bids are natural, Game Forcing, and inquire about support.
With xxx simply support the suit.
With Qxx or better, cue-bid first
round control even if holding a minimum.
  3 NT   This is a sign-off bid.
  4 club   Gerber. 5club asks for Kings and 4 No Trump is a sign-off.
  4 NT   Quantitative invitation to 6 No Trump.
  5 NT   Quantitative invitation to 7 No Trump. Opener must bid 6 No Trump with a minimum.
1 NT   2 club Stayman.
2 diamond   2 heart/2 spade   These bids by the responder are to play.
They do not necessarily indicate 5/4 in the Majors.
  2 NT   Invitational, because 1 NT - 2NT is Baron.
  3 club   6-card Club suit with one top honor missing and the expectation of an outside entry. The Ace or the King may be missing, but the Queen must be present. Strong invitation to 3 No Trump. For example: KQJxxx and an outside King. Note: with Diamonds there is no bid available to describe this hand, therefore, pass or bid 3 No Trump.
  3 diamond   Game Forcing and asking about distribution. The opener's responses are included below.
  3 heart/3 spade   Invitational, 6-card plus suit, and asks the opener to bid 4 Hearts, 4 Spades with outside top cards.
  3 NT   Sign-off bid.
       

For the purposes of the 3 Diamond Game Forcing inquiring bid, Kxx or Axx is good support and QJx is borderline.
The responses are:

Opener   Responder   Meaning
1 NT   2 club   Stayman by responder
2 diamond   3 diamond   Game Forcing and asking about distribution.
3 heart   Shows 2 Spades, 3 Hearts.
Then a 4club bid by the responder asks for strength in the Major.
3 spade   Shows 3 Spades, 2 Hearts.
Then a 4 club bid by the responder asks for strength in the Major.
3 NT   Shows 3 Spades, 3 Hearts, and poor strength in the Majors.
4 club   Shows 3 Spades, 3 Hearts, but better Hearts.
4 diamond   Shows 3 Spades, 3 Hearts, but better Spades.
4 heart   Shows 3 Spades, 3 Hearts, and both adequate.

The above 4 Club Major strength inquiry bid indicates Slam interest and the responses are:

Opener   Responder   Meaning
1 NT   2 club   Stayman by responder.
2 diamond   3 diamond   Game Forcing and asking about distribution.
3 heart/3 spade/4 club   See above.
4 diamond   Poor support in both Majors.
4 heart   Good support in both Majors.
4 spade   Good support in both Majors. Perhaps Kx/Axx or Ax/QJx.

Opener   Responder   Meaning
1 NT   2 club   Stayman by responder.
2 heart   3 spade   Invitational, 6-card plus suit, asks opener to bid 4 Spades with outside top cards.
1 NT   2 NT   Baron - Game Forcing. Suggesting slam.
3 spade   4 spade   4 Spades shows Slam interest, otherwise responder would have used Stayman, but with a poor 4-card Spade support.
4 spade   Good support in both Majors. Perhaps Kx/Axx or Ax/QJx.
1 NT   3 club   This bid is natural, Game Forcing, and inquires about support.
3 diamond   Shows Honor-xx+ in Clubs and Ace of Diamonds.
3 heart   Shows Honor+xx+ in Clubs and Ace of Hearts, but denies the Ace of Diamonds
3 spade   Shows Honor-xx+ in Clubs and Ace of Spades, but denies the Ace of Diamonds and the Ace of Hearts.
3 NT   Shows a doubleton in Clubs.
4 club   Shows three-card support in Clubs and denies Honor-xx+ Club support or the Ace of Diamonds, the Ace of Hearts and the Ace of Spades.

Opener   Responder   Meaning
2 NT   2 No Trump shows 19-20 high card points and a balanced hand. It may contain a 5-card Minor or a weak 5-card Major. This is to avoid rebidding the weak Major suit.
  3 club   3C is Baron over all 2 No Trump openings. However, the Flint 3 Diamond convention is not played over any 2 No Trump openings.
  2 NT/3 club   Features of the Baron System.
  3 diamond/3 heart/3 spade   Are all natural bids, and they are Game Forcing, asking about support. With xxx support, simply support the suit. With Qxx or better, cue-bid first round control, even if minimum.
  3 NT   Sign-off.
  4 club   Gerber. 5club asks for Kings and 4 No Trump is a Sign-off.
  4 diamond   Solid Diamond suit, invites cue bids.
  4 NT   Quantitative Invitation to 6 No Trump.
  5 NT   Quantitative invitation to 7 No Trump.
Opener must bid 6 No Trump with a minimum.
       

Important Side Notes

1. All 2 No Trump openings may contain a 5-card Major suit. 2 No Trump may be opened instead of 1 Heart or 1 Spade to avoid rebidding the weak Major suit. 2 No Trump may have to be rebid over 2 Clubs or 2 Diamonds because an Acol Two should contain a 6-card suit. 2 No Trump may have to be rebid over 2 Diamonds or 2 Hearts because the Major suit is too weak to suggest as a trump suit.
2. It is impossible to make a forcing Club bid over a 2 No Trump opening. However it is possible to make a forcing Club bid over the auctions: 2club - 2diamond - 2NT, and 2diamond - 2heart - 2NT.
3. The responses to the bidding auctions: 2club - 2diamond - 2NT, and 2diamond - 2heart - 2NT are the same as above, except for 4club, which is not Gerber. In the bidding auctions: 2club - 2diamond - 2NT and 2diamond - 2heart - 2NT a bid of 4club shows a 6-card solid Club suit with one top honor, such as the Ace or the King missing, but having the Queen. It is forcing as far as 4 No Trump.

Strong Openings - The strong opening bids in George Jesner's System are 2 Clubs and 2 Diamonds.

A 2 Clubs bid shows 8+ Quick Tricks in an unspecified suit or 21-22 high card points or 25-26 high card points and a balanced hand, and a 2 Diamonds bid shows a Game Forcing hand or 23-24 high card points or 27-28 high card points and a balanced hand depending on the rebid of the opener. These openings also contain outside defensive playing tricks - at least 2.5 defensive tricks outside of opener's suit.

2 Clubs and 2 Diamonds opening bids are Asking Bids. They ask for certain honor combinations, namely Ace and a King of different suit, or Ace/King of the same suit, or King/King/King/King, or King/King/King/Queen, or King and Queen/King and Queen. Responder may give a positive response with these honor combinations or better. It must be noted that the combination: King/King/Queen/Queen is not sufficient for a positive response.

The negative responses over 2 Clubs and 2 Diamonds openings are 2 Diamonds and 2 Hearts respectively. Over opener's rebid, the cheapest bid in No Trump by the responder is a second negative.

2 Club Opening Bid

2 Clubs shows 8+ Quick Tricks in an unspecified suit or 21-22 high card points or 25-26 high card points and a balanced hand.

Note that an Acol Two Opening, except for 2 Clubs or 2 No Trump, is described as 8-9 Quick Tricks, forcing for one round, and showing either 6-card plus suit or possibly a two suiter. It also contains outside defensive playing tricks - around 2 to 2.5 defensive tricks outside of opener's suit.

Responses to 2 Club Openings

Opener   Responder   Meaning
2 club   2 diamond   Negative response denies positive combination. Remember the positive combinations are: AK or A/K or K/K/K/K or K/K/KQ or KQ/KQ. Remember that the combination: K/K/Q/Q is not sufficient for a positive response.
2 diamond   2 heart   Negative response denies positive combination. Remember the positive combinations are: AK or A/K or K/K/K/K or K/K/KQ or KQ/KQ. Remember that the combination: K/K/Q/Q is not sufficient for a positive response.
2 club   2 heart   5-card plus suit, unless the distribution of the responder is 4-4-4-1, 4-4-1-4, or 1-4-4-4, but is a natural bid with a positive combination.
2club/2diamond   2 spade   5-card plus suit, unless the distribution of the responder is 4-1-4-4, but is a natural bid with a positive combination.
2club/2diamond   2 NT   Balanced hand, and any 4-3-3-3 or 4-4-3-2 distribution, but a natural bid with positive combination.
2club/2diamond   3 club   5-card plus suit, but a natural bid with a positive combination.
2club/2diamond   3 diamond   5-card plus suit, but a natural bid with a positive combination.
2club/2diamond   3 heart   Solid suit, which may play opposite a void for no losers. Cuebids follow.
2club/2diamond   3 spade   Solid suit, which may play opposite a void for no losers. Cuebids follow.
2club/2diamond   3 NT   Shows 2 Aces and a balanced hand.
2club/2diamond   4 club   Solid suit, which may play opposite a void for no losers. Cuebids follow.
2club/2diamond   4 diamond   Solid suit, which may play opposite a void for no losers. Cuebids follow.

Opener's Rebid Over 2 Diamond Response

Opener   Responder   Meaning
2 club   2 diamond   Negative response denies positive combination.
2 heart/2 spade/3 club/3 diamond   8 playing tricks in suit bid.
2 NT   21-22 high card points and balanced hand.
3 heart   4 Spades and 6 Hearts, 8-9 Quick Tricks but Non-Forcing.
3 spade   6 Spades and 4 Hearts, 8-9 Quick Tricks but Non-Forcing.
3 NT   25-26 high card points and balanced hand.

Second Negative

Opener   Responder   Meaning
2 club   2 diamond   Negative response denies positive combination.
2 heart   2 spade/2 NT   Second negative Also refers to distribution with a stopper or values.
2 club   2 diamond   Negative response denies positive combination.
3 club   3 diamond/3 NT   Second negative. Also refers to distribution with a stopper or values.

Responder's Jump Suit Response After A Negative

Opener   Responder   Meaning
2 club   2 diamond   Negative response denies positive combination.
2 heart/3 spade/4 club/4 diamond   Shows a solid 6-card plus suit with one of the two top honors missing.
2 club   2 diamond   Negative response denies positive combination.
3 spade/4 club/4 diamond/4 heart   Shows a solid 6-card plus suit with one of the two top honors missing.
2 club   2 diamond   Negative response denies positive combination.
3 club/4 diamond/4 heart/4 spade   Shows a solid 6-card plus suit with one of the two top honors missing.
2 club   2 diamond   Negative response denies positive combination.
3 diamond/4 heart/4 spade/5 club   Shows a solid 6-card plus suit with one of the two top honors missing.
2 club   2 diamond   Negative response denies positive combination.
2 NT/3 club   Baron
3 diamond/3 heart/3 spade/4 club   These are natural bids, Game Forcing, and asks about support. With xxx support, simply support the suit. With Qxx or better cuebid first round control, even if minimum.
3 NT   Sign-off.
4 diamond   Solid Diamond suit, invites cuebids.
4 NT   Quantitative invitation to 6 NT.
5 NT   Quantitative invitation to 7 NT.
The opener must bid 6 NT with a minimum.
2 club   2 diamond   Negative response denies positive combination.
3 NT
4 club
  Baron
4 diamond   Game force with good Diamond suit.
4 heart/4 spade.5 club/5 diamond   Sign-off bids.
4 NT   Quantitative bid.
5 heart/5 spade   Invitational to 6 Hearts, 6 Spades respectively with good trumps.

Opener's Rebid After A Positive Response

Opener   Responder   Meaning
2 club   2 NT   Balanced hand, and any 4-3-3-3 or 4-4-3-2 distribution, but a natural bid with positive combination.
3 club   Baron
3 NT   Sign-off.
3 diamond/3 heart/3 spade/4 club   These bids set the trump suit and leads to cue bids.
2 club   2 heart   5-card plus suit, and is a natural bid with a positive combination.
2 spade   Acol 2 Spade opener, strong 5-card plus suit, and could contain a second suit.
2 NT   21-22 high card points, balanced hand, and denies 4-card Heart support.
3 NT   25-26 high card points, balanced hand, and denies 4-card Heart support,

Over Interference

Opener   Overcaller   Responder   Overcaller
Partner
  Meaning
2 club   Any Overcall   Pass   Forcing, but nothing to bid.
Double   Penalty Double
2 club   Any Overcall   Any unbid Suit   Positive response with good suit.
2 club   Any Overcall   Pass   Pass   Forcing, but nothing to bid.
Double   Shows balanced hand 21+ high card points.
Suit Bid   Acol Two in that Suit.

2 Diamond Opening Bid

A 2 Diamonds opening bid shows a game forcing holding or 23-24 high card points or 27-28 high card points balanced hand.

Responses To 2 Diamond Openings

Opener   Responder   Meaning
2 diamond   2 heart   Negative response denies positive combination. See above for Positive Combinations.
  2 spade   5-card plus suit, unless responder has 4-4-4-1, 4-4-1-4 or 4-1-4-4.
  2 NT   Balanced hand, any 4-3-3-3 or 4-4-3-2, natural with positive combination.
  3 club   5-card plus suit, unless responder is 1-4-4-4, natural with positive combination.
  3 diamond   5-card plus suit, natural with positive combination.
  3 heart   5-card plus suit, natural with positive combination.
  3 spade   Solid suit, which may play opposite void for no losers. Cuebids follow.
  3 NT   Shows 2 aces and balanced hand.
  4 club   Solid suit, which may play opposite void for no losers. Cuebids follow.
  4 diamond   Solid suit, which may play opposite void for no losers. Cuebids follow.
  4 heart   Solid suit, which may play opposite void for no losers. Cuebids follow.

Opener's Rebid Over 2 Hearts Response

Opener   Responder   Meaning
2 diamond   2 heart   Negative response denies positive combination. See above for Positive Combinations.
2 spade/3 club/3 diamond/3 heart   Game force in suit bid.
2 NT   23-24 high card points and balanced hand.
3 spade/4 club/4 diamond/4 heart   Indicates a Solid suit. Cuebidding begins.
3 NT   27-28 high card points and balanced hand.

Second Negative

Opener   Responder   Meaning
2 diamond   2 heart   Negative response denies positive combination. See above for Positive Combinations.
2 spade/3 club/3 diamond/3 heart   2 NT/3 NT/3 NT/3 NT   The negative responses over 2 Clubs and 2 Diamonds openings are 2 Diamonds and 2 Hearts respectively. Over opener's rebid, the cheapest bid in No Trump by the responder is a second negative.
2 diamond   2 heart   Negative response denies positive combination. See above for Positive Combinations.
2 spade/3 club/3 diamond/3 heart   3 club/3 diamond/3 heart/3 NT   Each rebid by the responder is an alternative method of indicating a second negative by bidding the cheapest suit possible above the rebid by opener.

Responder's Jump Suit Response After A Negative Response

Opener   Responder   Meaning
2 diamond   2 heart   Negative response denies positive combination. See above for Positive Combinations.
2 spade/4 club/4 diamond/4 heart   Each rebid shows a solid 6-card plus suit, with one of the two top honors missing.
3 club/4 diamond/4 heart/4 spade   Each rebid shows a solid 6-card plus suit, with one of the two top honors missing.
3 diamond/4 heart/4 spade/5 club   Each rebid shows a solid 6-card plus suit, with one of the two top honors missing.
3 heart/4 spade/5 club/5 diamond   Each rebid shows a solid 6-card plus suit, with one of the two top honors missing.

After a Negative Response, opener bids or Jump bids. These bids are Forcing and responder must bid again, even if it is a Second Negative bid.

Opener   Responder   Meaning
2 diamond   2 heart   Negative response denies positive combination. See above for Positive Combinations.
2 NT   3 club   Baron
3 diamond/3 heart/3 spade/4 club   Natural bids, Game force, asks about support, with xxx support simply support the suit, with Qxx or better cue-bid first round control (even if minimum).
3 NT   Sign-off.
4 diamond   Solid Diamond suit, invites cue bids.
4 NT   Quantitative invitation to 6 NT.
5 NT   Quantitative invitation to 7 NT. Opener must bid 6 NT with a minimum.

Opener   Responder   Meaning
2 diamond   2 NT   Balanced hand, any 4-3-3-3 or 4-4-3-2, natural with positive combination.
3 club   Baron
3 NT   Sign-off.
3 diamond/3 heart/3 spade/4 club   These rebids by the opener sets the trump suit and leads to cue bids.
2 diamond   2 heart
3 NT   4 club   Baron
4 diamond   Game force with good Diamond suit.
4 heart/4 spade/5 club/5 diamond   Sign-off.
4 NT   Quantitative.
5 heart/5 spade   Invitational to 6 Hearts or 6 Spades with good trumps.

Over Interference

Opener   Overcaller   Responder   Meaning
2 diamond   Any higher unbid suit.   Pass   Forcing pass.
Double   Penalty Double
Any Suit rebid   Positive response with good suit.
2 diamond   Any higher unbid suit.  

Responder passes.
Partner of Overcaller passes.

Double   Shows balanced hand and 23+ high card points.
Any Suit rebid   Game Force in that suit.
     

Baron, Clubs or Gerber - Consistent agreement is needed whether the following similar sequences are Baron, Gerber, or merely show Clubs:

Opener   Responder   Meaning
2 club   2 NT   Positive response.
3 club   Baron
4 club   Baron
2 club   3 NT   Positive response.
4 club   Clubs
5 club   Clubs

Gerber is probably unnecessary in these sequences because opener can bid a suit and later Blackwood.

2 Hearts, 2 Spades Opening Bids

Weak two bid. 4-9 high card points, 6-card suit (quality undescribed but less than AKxxxx).
Denies a void. 1 to 1.5 defensive tricks in any suit.

Opener   Responder   Meaning
2 heart   2 spade   Forcing for one round.
  2 NT   Feature asking. Game forcing.
Opener's Responses
3 heart   Nothing outside of Hearts.
3 NT   Random bits and pieces outside.
3 of any suit   High card or potentially stopper.
3 club/3 diamond   Natural bid. Forcing for one round.
3 heart   Preemptive
3 spade/4 club/4 diamond   Good suit, game force, requests cuebid.
3 NT   Sign-off.

Opener   Responder   Meaning
2 spade   2 NT   Feature asking. Game forcing.
Opener's Responses
3 spade   Nothing outside of Spades.
3 NT   Random bits and pieces outside.
3 of any suit       High card or potentially stopper.
3 club/3 diamond/3 heart   Natural bid. Forcing for one round.
3 spade   Preemptive
3 NT   Sign-off.
4 club/4 diamond/4 heart   Good suit, game force, requests cue-bid.
     

Preemptive Bids

Opener   Meaning
3 NT   Broken 8-card minor suit pre-empt.
4 club/4 diamond   Preemptive opening bids.
4 heart/4 spade   Preemptive opening bids. Possibly lacking the defensive trick requirements for an Acol 2 bid.
4 heart/4 spade/5 club/5 diamond   Preemptive opening bids.
4 NT
Standard Preempt
  Acol 4 NT Opening Bid - For responses for Ace Showing click on the link.
5 heart/5 spade   Responder raises one level for each Top Honor held = Ace or King.
6 club/6 diamond/6 heart/6 spade   Responder raises one level for each Top Honor held = Ace or King.
     

4 Clubs is Gerber

4 Clubs is Gerber after opening bids of:

1 club
1 diamond
1 heart
1 spade
1 NT
2 heart
2 spade
2 NT

These are the only situations where Gerber applies.

After 1 No Trump and 2 No Trump opening bids and the response to Gerber, 4 No Trump is a signoff, and 5 Clubs asks for Kings. However after 1 Club, 1 Diamond, 1 Heart, 1 Spade, 2 Hearts and 2 Spades openings and the response to Gerber, 4 No Trump, if available, asks for Kings.

Asking for Kings guarantees that all the Aces are held, and responder may Jump to a Grand Slam with a source of tricks. It does not necessarily show Grand Slam interest. The partnership may still play in game.

4 No Trump Quantitative

4NT is quantitative in the following auctions:

1 No Trump - 4 No Trump
2 No Trump - 4 No Trump

Benjamin Two Followed by a Negative Response

The Benjamin Convention differs from the Weak Two Bid used in American 5-Card Standard, in that the 2 Diamonds bid is no longer used as a Weak Two Bid, but rather as an Artificial Strong Two Bid, as is the 2 Clubs bid when opening. In the following bidding auctions, the responder shows a Negative response:

2 club - 2 diamond
2 NT - 4 NT
3 NT - 4 NT

Benjamin Two Followed by a Positive Response

2 club - 2 NT
2 club - 3 NT

2 diamond - 2 NT
2 diamond - 3 NT

4 No Trump Blackwood

4 No Trump is always Blackwood unless the auction defines the 4 No Trump bid as quantitative.
1 No Trump or 2 No Trump - 4 Clubs - any response - 4 No Trump is a signoff after Gerber, and an opening bid of one or 2 Hearts or 2 Spades - 4club - any response - 4NT is Gerber asking for Kings.

Responder only shows a void suit over Blackwood which he feels may be the key to a Slam or Grand Slam. Do not bid above the level of the trump suit, if one is agreed or probably agreed. A bid of Six of the Trump Suit shows a void in a higher-ranking suit.

After the response to Blackwood, 5 No Trump guarantees possession of all the Aces and asks for the number of Kings held. Therefore the Blackwood initiator has Grand Slam interest. The responses are:

5 NT   6 club: zero Kings
  6 diamond: 1 King
  6 heart: 2 Kings
  6 spade: 3 Kings
  6 NT: 4 Kings
  7 of a suit: Shows an undisclosed source of Quick Tricks.

In the unlikely event that the opponents intervene, a Double is for Penalty, a Pass is Neutral suggesting no interest in slam, and Step Responses imply slam interest. The first Step Response would be to show an Ace.

In the unlikely event that the opponents intervene in an extreme manner, a Double shows zero or two Aces or an even number, a Pass shows one or three Aces or an odd number. If all four Aces are held, then the bidding auction should proceed as in the DEPO convention.

Information about the Auctions:
4th Suit is not forcing.

Change of suit at the Three Level is Game Forcing.
However, the sequence 1spade - 2diamond - 2heart - 3club is Non-Forcing.

Opener's Reverse Bids are an inferentially Forcing bids. They show about 16-19 high card points, or equivalent distribution. The responder may pass a Reverse Bid only if he should not have responded on the first round of bidding. However, if the opener reverses and responder bids again, then responder's rebid is Forcing for one round. The responder may rebid a strong suit, say KQJxxx with other values outside, to find out more about the hand.

Jump Reverses by opener are absolutely Game Forcing.

Responder's Reverse Bids are an inferentially a Forcing bid. Although the sequence 1diamond - 1heart - 2diamond - 2spade is highly encouraging and will seldom be passed, this sequence is Non-Forcing. Remember, 4th suit is not forcing.

After a force to game, a Jump in one of opener's suits determines that suit and shows a double fit. For example, after 1heart - 1spade - 3diamond, 3 heart would be preference and 4 Hearts would show good Hearts and good Diamonds, most likely a top honor in Diamonds.

Over a force by the responder, opener must show distribution. For example, 1heart - 3club - 3spade, 3 Spades shows a 4-card Spade suit and not necessarily any extra values.

Similarly, over a force by opener, the responder must show distribution. After the bidding auction: 1heart - 2club - 3diamond - 3NT the responder probably shows 3-2-3-5 distribution or even 3-1-3-6.

Auctions After An Opponent Doubles

After an opponent Doubles a One Level opening, a Pass says nothing about the holding, but promises at least doubleton support. A new suit shows a poor hand and void or singleton in opener's suit. A Jump in a new suit shows poor hand and a 6-card suit. A 1 No Trump bid shows 6-9 high card points, and is to play.

A single Raise shows 4-6 high card points but can be very weak. A Jump Raise is a Preemptive Raise and showing about 5-9 high card points. A Raise to Game is Preemptive with strong distribution. A 2 No Trump bid is a good raise showing 10-12 high card points and 4-card support. A Redouble shows about 10+ high card points and shows the balance of the points.

Defensive Bidding

Overcalls: Shows a 5-card plus suit and less than an opening hand, about 12 high card points. The emphasis is on good suit rather than point count. These overcalls are also Lead Directing. New suit responses are non-forcing.

Jumps and cuebids force overcaller to bid again.

Several bidding sequences:

  South   West   North   East   Meaning
1. 1 heart   1 spade   2 heart   3 spade   Non-Forcing.
2. 1 heart   1 spade   1 NT   3 spade   Non-Forcing.
3. 1 club   1 heart   Pass   1 spade   Non-Forcing. However, 2spade jump is forcing.
4. 1 club   1 heart   2 club   Double   Penalty Double.

Takeout Doubles: Shows an opening hand, about 12+ high card points, or better.

With 9+ high card points, the responder jumps in his longest suit.

A 1 No Trump response shows 6-9/10 high card points with a stopper in the opponent's suit.

Note: 1 heart - Double - Redouble - Pass denies 4 Spades. In general 1 suit - Double - Redouble - Pass denies four cards in the next higher ranking suit.

1 club - Double - 1 spade - Double shows Spades, by inference, and can be for penalty.

1 heart - Double - 2 heart - 3 club is not Forcing.

Redouble

North   East   South   West
1 heart   Double   Redouble   Pass
Pass   1 spade   Double   Pass
Pass   Redouble
SOS convention
Kock-Weiner =
Both Minor Suits

Responsive Doubles

Responsive Doubles are used over opponent's raises to 3 Spades.
For example, the second double in the following auction is responsive.
1 spade - Double - 3 spade - Double

1 No Trump Overcall

Shows 15-17 high card points with a stopper in the opponent's suit/s in all positions.
1 diamond - Pass - 1 spade - 1 NT shows 15-17 high card points with a stopper in the opponent's suits.
Note the inference that partner could not even overcall.

Single Jump Overcall

Intermediate to strong with 6-7 playing tricks but not forcing. It also shows 2 defensive tricks. 15 high card points plus. Good 6-card suit. Usually denies a full stopper in the opponent's suit. With a stopper in the opponent's suit, commence with a double. After the bidding sequence: 1 heart - 2 spade - Pass - 3 heart, the responder shows half a stopper.

Jump overcalls are weak against artificial systems.

A study of the defense to Precision is advised.

Cue-bid

Always equals Game Force.

Jump Cue-Bid

Requests partner to bid No Trump with a stopper in the opponent's suit.
A Jump Cuebid typically shows a solid suit. See Western cuebid.

2 No Trump Overcall over One of a Suit

This bid shows a 6/5 distribution or better in the unbid suits.
It may be weak or strong. It is forcing for one round. It promises another bid.

Defensive Bidding

Doubles are Penalty Doubles.

Over a Precision Club Opening

1 club - Double indicates both Majors.
1 NT indicates both Minors.
2 club, 2 diamond, 2 heart, 2 spade are weak Jump Overcalls.

Over 1NT

1 No Trump - Double indicates 15 high card points plus, and may be a Penalty Double.
Any Suit bid is natural.
Three Level overcall indicates 6/7 playing tricks.

Over Opponent's Transfer

Response to 1 No Trump Bid
1 NT - Pass - 2 diamond - Double indicates Diamonds and some values.
2 heart indicates a weak hand, 4 Spades and longer Minor suit.
2 spade overcall indicates a long Spade suit: KQJ10xxx is sufficient.

Over Weak Two Bids

2 heart or 2 spade - Double is for Penalty.
2 NT indicates 15-18 high card points and good stoppers in the opponent's suit.
3 club is for Takeout.

Over Weak Three Bids

3-of any suit - Double is for Penalty.
Bidding the next suit is the Fishbein Takeout.

Leads and Signals

Overlead all except Ace-King.

The lead of an Ace against No Trump Contract, except the Gambling 3 No Trump, requests partner to play his highest card.

4th highest leads.

Against suit contracts lead Middle-Up-Down or MUD from three small and 4th highest or top from four small.
Against No Trump contracts, lead the top of nothing from three small and 4th highest or top from four small.

Natural encouragement and count signals. High-low is encouraging or even number.

McKenny Suit Preference Signals are used where obvious. In various countries, the Suit Preference Signal is known by the names of bridge writers. The McKenny Suit Preference Signals is a standard term in Great Britain simply for the Suit Preference, and it named for Mr. William E. Mckenny of the ACBL, who helped popularize it.

DUM or Down-Up-Middle

When following suit with say 742, play the 2, which is a preference signal or discouraging, then the 7 and then the 4, showing an odd number. When following suit with say 72, after playing the queen from Q72 per force, play 7 followed by the 2, showing an even number.

This concludes the material regarding the Acol System written by Mr. George Jesner. It is comprehensive and involved and also requires a lot of memorization. However, once this has been mastered, this version could lead to a good partnership. If you decide to adopt this version of the Acol System with all of its modifications, then it is necessary that you inform your opponents at the bridge table that you have adopted this system. Please enter it on your Convention Chart in the appropriate places.

 

 

If you wish to include this feature, or any other feature, of the game of bridge in your partnership agreement, then please make certain that the concept is understood by both partners. Be aware whether or not the feature is alertable or not and whether an announcement should or must be made. Check with the governing body and/or the bridge district and/or the bridge unit prior to the game to establish the guidelines applied. Please include the particular feature on your convention card in order that your opponents are also aware of this feature during the bidding process, since this information must be made known to them according to the Laws of Duplicate Contract Bridge. We do not always include the procedure regarding Alerts and/or Announcements, since these regulations are changed and revised during time by the governing body. It is our intention only to present the information as concisely and as accurately as possible.

 


     
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