An html version of Nowotny.cql.

Created by Gady Costeff and Lewis Stiller.

CQL 5.1

; White sacrifices an officer on an unguarded empty square
; Black can recapture with rook or bishop
; the interference theme is considered, so this has false positives

cql(input heijden.pgn variations sort matchcount 1 100 result 1-0)
 piece $sacrifice in [RBNQ]b-g2-7
   move from $sacrifice to .
    not attacks (A $sacrifice)
    move from r to $sacrifice
    move from b to $sacrifice

CQL 3.2
;search for nowotny theme with rook and bishop interference: ;; white moves to a square that is, on the next move, moved to either by a Black rook or a Black bishop; ;; do the same with white and black interchanged ;; We do not check that the Nowotny is "thematic" in the sense that the rook and the bishop ;; actually interfere thematically with one another. For example, this will include positions in which ;; the "nowotny" occurs on the edge of the board. ;; Comment Lewis Stiller: False positives.
(match :pgn heijden.pgn :output nowotny.pgn (position :moveto .b2 ;; The following line, if uncommented, filters out edge ;; Nowotny's which are not true Nowotny's from occurring on the edge of the board. ; ?b1 ?a1 ?a2 ?a3 ?b3 ?c3 ?c2 ?c1 :wtm :and ((position :sequence ((position :moveto .b2) (position :movefrom b :moveto Ab2))) (position :sequence ((position :moveto .b2) (position :movefrom r :moveto Ab2))) ) :shift :markall :variations :flipcolor ) )

After executing this with "> cql Nowotny.cql" there are 511 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 a few studies are presented: