White plays and mates in 4 moves
Key: 1.Sg3! [2.Se2#] Re8
2.Rbc2 [3.R2c4#] Bxc2
3.Sfe4 [4.Bc3#]. (The Springer (=Knight) move aims to cut the influence lines of the black Rook and Bishop and, if Sf4 is captured, to threaten mate with Sg3 from two places).
3...Bxe4 / Rxe4
4.Se2# / Sf5#
|Theme Nowotny intersection : it is a square, which is Grimshaw intersection for black pieces with dissimilar linear movement, and on which a white piece is placed in order to cut the black lines and to force black pieces (when they capture the white piece) to mutually interfere.|
White Nowotny : it is an intersection of white pieces with dissimilar linear movement, and on this intersection a black piece is placed, in order to force white pieces to mutually interfere.
Second Prize, BCPS Ring Tourney, 1966
White plays and mates in 2 moves
With a Nowotny intersection, the white has simultaneously two threats.
In Lipton’s problem we must locate which square is the Nowotny intersection and also discover which piece must be sacrificed there!
(Should become Nowotny the Grimshaw intersection e5?)
Try: 1.Be5? [2.Sg7# / Re7#] Sxh7!
(Or should become Nowotny the Grimshaw intersection d4?)
Try: 1.Sd4? [2.Sf6# / Rd8#] Re7!
Try: 1.Rd4? [2.Sf6# / Sd6#] Re6!
Key: 1.Bd4! [2.Sg7# / Rd8#] Se6 2.Re7#
[This post in Greek language].