An html version of samecolorbishops.cql.

Created by Gady Costeff and Lewis Stiller.

CQL 5.1
; At least two bishops of same color and square color cql(input heijden.pgn) flipcolor flipvertical countsquares 2 9 B on lightsquares

CQL 3.02
; Search for games with that have either two light-squared white ;bishops, two dark-squared white bishops, two dark-square black ;bishops. or two light-square black bishops. ;There are two ways to do this. One is to simply have a giant :or with 4 ;:piececount clauses in the or: ;(position ; :or( ; (position ; :piececount B[a1,a3,a5,a7,b2,b4,b6,b8,c1,c3,c5,c7,d2,d4,d6,d8,e1,e3,e5,e7,f2,f4,f6,f8,g1,g3,g5,g7,h2,h4,h6,h8] 2 9 ) ; (position ; :piececount b[a1,a3,a5,a7,b2,b4,b6,b8,c1,c3,c5,c7,d2,d4,d6,d8,e1,e3,e5,e7,f2,f4,f6,f8,g1,g3,g5,g7,h2,h4,h6,h8] 2 9) ; (position ; :piececount b[a2,a4,a6,a8,b1,b3,b5,b7,c2,c4,c6,c8,d1,d3,d5,d7,e2,e4,e6,e8,f1,f3,f5,f7,g2,g4,g6,g8,h1,h3,h5,h7] 2 9) ; (position ; :piececount B[a2,a4,a6,a8,b1,b3,b5,b7,c2,c4,c6,c8,d1,d3,d5,d7,e2,e4,e6,e8,f1,f3,f5,f7,g2,g4,g6,g8,h1,h3,h5,h7] 2 9) ; ) ;) ; But a more elegant way is to use the following code, which relies on ; the fact that flipping the board horizontally changes the color of the ; squares: (match :pgn heijden.pgn :output samecolorbishops.pgn (position :piececount B[a1,a3,a5,a7,b2,b4,b6,b8,c1,c3,c5,c7,d2,d4,d6,d8,e1,e3,e5,e7,f2,f4,f6,f8,g1,g3,g5,g7,h2,h4,h6,h8] 2 9 :flipcolor :fliphorizontal :markall ) )

After executing this with "> cql SameColorBishops.cql" there are 283 studies found in the Harold van der Heijden Database 2015.
NB. When you see {MATCH} in the text, it means that cql has found the position asked for.

Below only 5 studies ares showed: