... by: Norman Powell
AS's solver makes 8 eliminations before running out of techniques:X-Cycles 4D1, Forcing Nets 1A7, 6D5, 6D7, 7E1, 9J7, 7E2, 7E3
My Solver solves this puzzle after the 5 Pass through Forcing Networks, which finds a solution testing 8D3 for ON.
Details:
Finned Swordfish: BD2G67 with Fin E2 for Value 4 - Eliminate 4D1 from Fin Box. [AS #1 X-Cycles]
[I have all the finned fish earlier than Forcing Networks in the list of methods, as they are fast searches on single values, faster than my implementation of X-Cycles, which is slower than my Forcing Networks, so currently appears after Forcing Networks]
Forcing Networks First Pass: The following create contradictions when ON so eliminate:
1A7 [AS #2], 6D5 [AS #3], 6D7 [AS #4], 9J7 [AS #6]
Forcing Networks Second Pass: The following create contradictions when ON so eliminate:
7E1 [AS #5], 7E2 [AS #7], 7E3 [AS #8]
Forcing Networks Third Pass: The following create contradictions when ON so eliminate:
3A7, 9B8
Forcing Networks Fourth Pass: The following create contradictions when ON so eliminate:
7A1, 7D1, 7D2, 7D3, 3F9, 3G8, 1H2, 9J4, 9J5
Hidden Single H9 = 9
Confined to Box: 7 is confined to Row F and Box 4, eliminate other 4's in Row F or Box 4.
Hidden Triplet in Colum 7 for values 4 7 9 in Cells A7, B7 and D7, eliminate other possibilities in those cells.
Confined to Box: 1 is confined to Column 7 and Box 9 eliminate other 1's in Column 7 and Box 9
Forcing Networks Fifth Pass: Makes 15 suggestions for elimination before finding a solution testing 8D3 for ON.
Solved in 2mins 11secs on VBA solver in Excel.