Chameleon

return"Chameleon",function(t,t2)
	local set,names={},{}
	local function rep()
		local r,len=math.random(3)-1,0
		for i=#t-1,1,-1 do
			local v=t[i+1]
			for j=0,i do
				if t[i-j]==t[#t-j]and t2[i-j]==t2[#t2-j]then
					if j>=len then
						r,len=(v+1)%3,j+1
					end
				else
					break
				end
			end
		end
		return r
	end
	names[rep]="rep"
	local function rep2()
		local r,len=math.random(3)-1,0
		for i=#t-1,1,-1 do
			local v=t[i+1]
			for j=0,i do
				if t[i-j]==t[#t-j]then
					if j>=len then
						r,len=(v+1)%3,j+1
					end
				else
					break
				end
			end
		end
		return r
	end
	names[rep2]="rep2"
	local function repbias()
		local a,b,c=0,0,0
		for i=#t-1,1,-1 do
			local v=t[i+1]
			for j=0,i do
				if t[i-j]==t[#t-j]then
					local n=3^j/(#t-i)
					if v==0 then a=a+n elseif v==1 then b=b+n else c=c+n end
				else
					break
				end
			end
		end
		if a>b and a>c then return 1
		elseif b>a and b>c then return 2
		elseif c>a and c>b then return 0
		elseif a>b and a==c then return 0
		elseif b>c and b==a then return 1
		elseif c>a and c==b then return 2
		else return math.random(3)-1 end
	end
	names[repbias]="repbias"
	local function hist()return #t==0 and math.random(3)-1 or(t[math.random(#t)]+1)%3 end
	names[hist]="hist"
	local function hist3()return #t==0 and math.random(3)-1 or(t[math.random(math.max(1,#t-3),#t)]+1)%3 end
	names[hist3]="hist3"
	local randbias do
		local r,p,s=0,0,0
		local function f(x)
			if x==0 then r=r+1 elseif x==1 then p=p+1 else s=s+1 end
		end
		for i=1,#t do f(t[i])end
		randbias=function()
			if #t~=0 then f(t[#t])else return math.random(3)-1 end
			local x=math.random(r+p+s)
			if x<=r then return 1 end
			if x<=r+p then return 2 end
			return 0
		end
	end
	names[randbias]="randbias"
	local even do
		local r,p,s=0,0,0
		even=function()
			if math.random(2)==1 then
				if p>r and r < s then r=r+1 return 0 end
				if p < r and p < s then p=p+1 return 1 end
				if s < r and p>s then s=s+1 return 2 end
				if r < s and p < s then if math.random(2)==1 then r=r+1 return 0 else p=p+1 return 1 end end
				if p>r and p>s then if math.random(2)==1 then r=r+1 return 0 else s=s+1 return 2 end end
				if p < r and s < r then if math.random(2)==1 then p=p+1 return 1 else s=s+1 return 2 end end
			end
			local n=math.random(3)-1
			if n==0 then r=r+1 elseif n==1 then p=p+1 else s=s+1 end
			return n
		end
	end
	names[even]="even"
	local f={}for a,_ in pairs(names)do f[#f+1],set[a]=a,0 end
	for i=1,#f do local x=function()t,t2=t2,t local r=f[i]()t,t2=t2,t return r end set[x]=0 names[x]="anti"..names[f[i]]f[#f+1]=x end
	for i=1,#f do local x=function()return(f[i]()+1)%3 end local y=function()return(f[i]()+2)%3 end set[x]=0 set[y]=0 names[x]=names[f[i]].."+1" names[y]=names[f[i]].."+2"end
	local function rand()return math.random(3)-1 end set[rand]=0 names[rand]="rand"
	local last={}
	return function()
		local r=t[#t]
		local name="rand"
		if r then
			local mv,m=-math.huge,rand
			for f,v in pairs(set)do
				local a,b=last[f],r
				if a==(b+1)%3 then
					v=v+1 set[f]=v
				elseif a~=b then
					v=v-1 set[f]=v
				end
				if v>mv then m,mv=f,v end
			end
			ret=m()name=names[m]
		else
			ret=rand()
		end
		for f,v in pairs(set)do last[f]=f()end
		return ret
	end
end