Introduction                                                    9th June 2020
    ============
    The first bridge course that I attended taught British Acol. Not many
    people play that in Switzerland, so my system has been modified ad hoc
    over the years to come into line with more common practices in Switzerland.

    Basic Maxims
    ============
    1. Bid as high as possible, as early as possible, then back off.
    
    2. Unless very weak, try not to let opponents play at the 2-Level
       or less in a suit of their choice. But beware of partner
       misinterpreting and pushing them into a makeable game that they
       otherwise would not have reached.

          HCP = High Card Points
          SP  = Strength Points = HCP + distribution pts.
                Note: SP can only be used if there is a trump fit.
    
    Opening Bids:
    ============
    An opening bid promises 12+ HCPs
                         or 7 or less losers
                         or Rule of Twenty (sum of HPs and number of cards
                            in the 2 longest suits is 20 or more).
    
    1C     may be a doubleton in clubs (See "Better Minor" below). It
           should not be passed. A 1D response shows a weak hand or diamond
           suit.
    1D     promises 4 or more D and no 5-card major suit
    1H/1S  5+ card suit
    1NT    15-17 HCP, no void, no singleton, at most one doubleton and
                      no 5-card major suit. 2C response is Stayman. 2D
                      and 2H responses are transfers. 
    2C     Semi-forcing. Most likely a strong suit and 5 losers or less,
                         if the strong suit becomes trumps.
                         Response is 2D. Responder may pass before game is
                         reached.
    2D     Forcing to game, unless 2NT is next bid. Response gives strength:
                            2H  - less than 7 HCP, no Ace.
                            2S  - one Ace, but nothing else.
                            2NT - 2 Kings, or equivalent
                            3C  - one Ace and extra points too.
                            3D  - 2 Aces (or more - never happens).
    2H/2S  Weak 2, 6-card suit, 6-10 points, mainly in the 6-card suit. 2NT
                   response is special, see:
                       https://maden.ch/bridge/weakTwo/weakTwo.pdf
    2NT    20-21 HCP. At most 1 doubleton and at least a Kx block
                      in every suit.
    3C/3D/3H/3S   Barrage. Expect a -2 (vul) or -3 (non-vul) result with
                           no help from partner.
    
    Responses
    =========
    1) With 6-7 HCP or more, parter may not pass unless opponents have intervened.
    
    2) To respond at level 2 in a new suit, partner needs 10+ SP. Otherwise
          he must bid 1NT.
    
    Important: a response may be a 4-card suit, EVEN AFTER INTERVENING BID
                 from the opponents. Opener needs 4 cards in that suit
                 to support it.
    
    3) NT response is always limited: 1NT - 8 or less HCP. It may be
                                            a desperation bid.
                                      2NT - 9-11 HCP
    
    4) 4NT - Asking for Aces. Responses 5C: 0 or 3, 5D: 1 or 4, 5H: 2, 5S: 2 Aces + a King.
    
    Intervention (Overcall) Bids
    ============================
    1) A suit overcall shows 5+ card suit. Maybe quite weak - down to 8 HCP
                                           or a long suit.
    
    2) A double not preceded by a pass shows an opening hand and
       strength in the other suits.
    
    3) A double after having passed:
         a) if the opponents have bid a major suit, it shows 4 cards in the
            other major and probably 9-11 HCP.
    
         b) otherwise, probably shows length in the non-bid suits and
            9-11 HCP.
    
    4) Jump to 2H or 2S - see Weak-2 above.

    5) A redouble of opponent's take-out double indicates 8+ SPs.
    
    Opening Lead
    ============
    1) If partner has bid, I will lead my HIGHEST card in that suit.
    
    2) If partner has not bid, and the contract is NT, and I have no obvious
       minor suit lead, I will lead my WEAKER major suit (hoping to find partner's
       better suit - theory: if declarer had a decent major suit, it would
       be the trump suit. I will not normally lead suit bid by opponents, but may
       lead through suit bid by dummy.

    3) I do not lead from under a King.

    4) If my only option is to lead a suit with an Ace in it, I lead the Ace.
    
    Signals
    =======
    1) In suit contracts, high response is positive.
       In NT   contracts, low  response is positive.

    2) First Discard: Lavinthal

    Other Conventions, depending on Partner
    =======================================
    Better Minor: 1C indicates at least a 3-card suit, and the club suit
                     is longer than the diamond suit.
                  1D may indicate only a 3-card suit and the diamond suit
                     is longer than the club suit.
    
    Inverted Minor: Raising partner's opening of 1C or 1D to the 2 level is strong.
                    Raising partner's opening of 1C or 1D to the 3 level is pre-emptive.
    
    Bergen Raises:  Jump to 3C   => 4-card fit +  8-10 SPs
                    Jump to 3D   => 4-card fit + 11-12 SPs
                    Jump to 3H/S => 4-card fit +  0-7  SPs
                    2NT          => 3-card fit + 11-12 SPs
          If opponents intervene at 2+ level, Bergen is off and
          calls are natural.
    
    2D-Multi:     See: https://maden.ch/bridge/2KaroMulti/2KaroMulti.pdf
    
    4C - Asking for Aces. Only if there has been no bid of 3C.

    Drury:    2C response by a passed hand after partner opens 1H or 1S in third
              or fourth seat. Asks if opener's bid is weak or not.