# alias: ReverseByOpener
# button-text: Reverse By Opener
# gib-works: true
# bba-works: true
# auction-filter: (1C +Pass +1[HSN].*\n2D)|(1D +Pass +1[SN].*\n2H)|(1H +Pass +1NT.*\n2S)
# curate: kind=bidding
# convention-card-ns: 21GF-DEFAULT
# convention-card-ew: 21GF-GIB

/*@chat
--- Reverse By Opener
Reverses show 5+ cards in the suit opened and 4+ cards (usually) in the suit rebid.  They are natural
and strong -- in the 17-21 range -- a 1-round force.  Possible Reverses by Opener are...
  • 1!H - 1N - 2!S
  • 1!D - 1!S - 2!H
  • 1!D - 1N - 2!H/2!S
  • 1!C - 1!H - 2!D
  • 1!C - 1!S - 2!D/2!H
  • 1!C - 1N - 2!D/2!H/1!S
Reverses are NOT a convention.  If you don't have the extra strength, don't reverse.  Some play lebensohl
after reverses -- second link below.
https://www.bridgebum.com/reverse_bids.php
https://www.advinbridge.com/this-week-in-bridge/417
4NT is Roman Keycard Blackwood (1430) with a trump suit agreed, or quantitative (inviting 6NT) in a notrump auction. Keycard responses:
  • 5!C = 1 or 4 keycards
  • 5!D = 0 or 3
  • 5!H = 2 without the trump queen
  • 5!S = 2 with the trump queen
@chat*/

# Reverse By Opener
dealer south

#include "script/Calm-Opponents"
#include "script/Predict-Opening-1-Bid"
#include "script/Predict-Response-to-1-Bid"
#include "script/Predict-Openers-Rebid"

sShape = shape(south,any 54xx+any 64xx)
reverse = (HNS or DSH or DNH or DNS or CHD or CSD or CSH or CND or CNH or CNS) and sShape
reverse and hcp(south)>16 and hcp(south)<22 and hcp(north)>5 and hcp(north)<13 and calmOpps