# alias: NegativeFreeBid
# button-text: Negative Free Bid
# gib-works: false
# bba-works: true
# auction-filter: 1[CDHS] (1[DHS]|2[CDHS]) [123][CDHS]
# convention-card-ns: 21GF-DEFAULT
# convention-card-ew: 21GF-GIB

/*@chat
--- Negative Free Bid
North Opens & East Overcalls and South has no Major suit fit w/North and
• 5-9 HCP with a good 5- or any 6-card suit (non-jump) or
• 10-11 HCP with a good 6+ card suit (jump)
https://kwbridge.com/bb/nfb-1.htm
@chat*/

# Negative Free Bid
dealer north

# Predict North's opening suit
sN = spades(north)
hN = hearts(north)
dN = diamonds(north)
cN = clubs(north)
nS = sN>4 and sN>=hN and sN>=dN and sN>=cN
nH = not nS and hN>4 and hN>=dN and hN>=cN
nD = not nS and not nH and ((dN>3 and dN>=cN) or cN<3)
nC = not nS and not nH and not nD

# Calculate North's Rank
nRS = nS ? 4 : 0
nRH = nH ? 3 : 0
nRD = nD ? 2 : 0
nRC = nC ? 1 : 0
northRank = nRS+nRH+nRD+nRC   // all except one are zero

# East's longest suit
sE = spades(east)
hE = hearts(east)
dE = diamonds(east)
cE = clubs(east)
eS = sE>=hE and sE>=dE and sE>=cE
eH = not eS and hE>=dE and hE>=cE
eD = not eS and not eH and dE>=cE
eC = not eS and not eH and not eD

# Calculate East's Rank
eRS = eS ? 4 : 0
eRH = eH ? 3 : 0
eRD = eD ? 2 : 0
eRC = eC ? 1 : 0
eastRank = eRS+eRH+eRD+eRC

# South's longest suit
s = spades(south)
h = hearts(south)
d = diamonds(south)
c = clubs(south)
sS = s>=h and s>=d and s>=c
sH = not sS and h>=d and h>=c
sD = not sS and not sH and d>=c
sC = not sS and not sH and not sD

# Calculate South's Rank
sRS = sS ? 4 : 0
sRH = sH ? 3 : 0
sRD = sD ? 2 : 0
sRC = sC ? 1 : 0
southRank = sRS + sRH + sRD + sRC

# East's Good Suits
eGS = eS and top3(east,spades)>1
eGH = eH and top3(east,hearts)>1
eGD = eD and top3(east,diamonds)>1
eGC = eC and top3(east,clubs)>1

# East's Good Suit
gSE = (eGS or eGH or eGD or eGC)

# North opens
northOpens = hcp(north)>11 and hcp(north)<15

# Kill east's takeout double and NT
eSfit = nS and spades(east)>1        // east has 2 or more of north's opening suit
eHfit = nH and hearts(east)>1
eDfit = nD and diamonds(east)>1
eCfit = nC and clubs(east)>1
eShape = (eSfit or eHfit or eDfit or eCfit) and shape(east, any 5332 +any 5431 +any 6331)
eastOvercalls = hcp(east)>10 and hcp(east)<15 and eShape and gSE

# South's Good Suits
sGS = sS and top4(south,spades)>2
sGH = sH and top4(south,hearts)>2
sGD = sD and top4(south,diamonds)>2
sGC = sC and top4(south,clubs)>2

# South's Good Suit
gSS = (sGS or sGH or sGD or sGC)

calm = shape(south, xxxx -any 76xx -any 75xx -any 66xx -any 65xx -any 55xx)
a6 = shape(south, any 7xxx +any 6xxx) and calm              // any 6+
g5 = gSS and shape(south, any 5xxx) and calm                // good 5


a6g5 = (a6 or g5) and (hcp(south) > 4 and hcp(south) < 10)  // (any 6+ or good 5) and 5-9
g6 = a6 and gSS and hcp(south) > 9 and hcp(south) < 12      // good 6+ and 10-12

rankOK = (northRank > eastRank) or (northRank > southRank) or (eastRank > southRank)   // eliminate 1-level bids for south

sFit = nS and spades(south)>2        //  eliminate hands where South has support for North's major
hFit = nH and hearts(south)>2
fitOK = not sFit and not hFit

southResponds = fitOK and rankOK and (a6g5 or g6) 

# Now do it
northOpens and eastOvercalls and southResponds