... by: Dieter

#705 - initially populated cells: 22 = 27,2 %
No solver used, solver = brain.
basics: %

Strategy: numbers 3,4,5,6 occur most frequently, combine two cells with almost same candidates.
combinations of D4 = (4,5,6,7) and D5 = (2,3,4,5)
after basic checks 5 matrices left: 4/2, 5/2, 5/4, 6/2 and 6/5
D4=6 & D5=2 solve with H5=8

... by: Norman Powell

This Puzzle can be solved by Forcing Networks (18 calls) with 2 Grouped Alternative Inference Chains, 1 Alternative Inference Chain, 2 3D Medusa, 2 X-Cycles, and some easier techniques. The solution is found by a forcing network, equivalent to Bowman's Bingo in Andrew Stuart's Solver.
Solution reports below up to final declarations of the solved cells, read from bottom up, rows numbered, columns lettered.

Forcing Networks Solution Found - Eliminate all Trial OFFs
3D Medusa For network of links
Rule 5: Value 7 in Cell G4 can see both colours - Eliminate
Rule 4: Value 7 has the both colours in Column 4
Eliminate other possibilities
3D Medusa For network of links
Rule 4: Value 4 has the both colours in Row 4
Eliminate other possibilities
Rectangular Elimination Value 8 ON in Cell E2 and Strong Link E9 B9 would elimnate all 8s from Box 1 - so Eliminate
Forcing Networks Value 8 in Row 9 Column G cannot be ON so eliminate
Contradiction: No possibilities left for Row 7 Column I
Forcing Networks Possibilities Forced to Same State when Value 1 in Cell A9 is ON or OFF
Eliminate Forced OFF Possibility: Value 7 in Cell I1
Eliminate Forced OFF Possibility: Value 2 in Cell I1
Alt. Inf. Chains Value 8 of Cell F7 has weak links to both ends of the chain
This possibility would cause a contradiction - Eliminate
Naked Triplets Naked Triplet in Row 9, for Values: 4 8 9 in Cells: B9 E9 G9
Naked Pairs Naked Pair in Box 1, for Values: 6 7 in Cells: C1 A2
Confined to Box Value 1 is confined to Column B and Box 1.
Hidden Singles In Box 7 A7 = 5.
In Column 2 B4 = 5.
Forcing Networks Value 5 in Row 9 Column B cannot be ON so eliminate
Contradiction: No possibilities left for Value 2 in Row 4
Forcing Networks Value 9 in Row 9 Column H cannot be ON so eliminate
Contradiction: No possibilities left for Row 8 Column G
Forcing Networks Value 7 in Row 9 Column G cannot be ON so eliminate
Contradiction: More than one Value ON in Row 3 Column F
Forcing Networks Value 9 in Row 9 Column F cannot be ON so eliminate
Contradiction: No possibilities left for Row 4 Column D
Forcing Networks Value 8 in Row 9 Column F cannot be ON so eliminate
Contradiction: No possibilities left for Row 7 Column I
Forcing Networks Possibilities Forced to Same State when Value 1 in Cell A9 is ON or OFF
Eliminate Forced OFF Possibility: Value 7 in Cell D6
Grouped Alt. Inf. Chains Value 7 of Cell C2 has weak links to both ends of the chain
This possibility would cause a contradiction - Eliminate
Grouped Alt. Inf. Chains Value 1 of Cell A2 has weak links to both ends of the chain
This possibility would cause a contradiction - Eliminate
Forcing Networks Value 1 in Row 9 Column B cannot be ON so eliminate
Contradiction: More than one Value 9 ON in Column F
Forcing Networks Possibilities Forced to Same State when Value 1 in Cell A9 is ON or OFF
Eliminate Forced OFF Possibility: Value 6 in Cell H9
Eliminate Forced OFF Possibility: Value 6 in Cell I5
Forcing Networks Value 5 in Row 9 Column A cannot be ON so eliminate
Contradiction: No possibilities left for Value 4 in Column G
Hidden Singles In Row 3 A3 = 3.
In Row 1 E1 = 3.
Cell B8 = 3
Forcing Networks Value 3 in Row 8 Column B cannot be OFF so eliminate other values
Contradiction: No possibilities left for Value 6 in Row 1
Forcing Networks Value 9 in Row 9 Column E cannot be ON so eliminate
Contradiction: No possibilities left for Value 1 in Row 4
Confined to Box Value 2 is confined to Column A and Box 4.
Forcing Networks Value 2 in Row 4 Column B cannot be ON so eliminate
Contradiction: More than one Value ON in Row 6 Column F
Forcing Networks Value 6 in Row 5 Column D cannot be ON so eliminate
Contradiction: More than one Value ON in Row 1 Column I
Forcing Networks Value 2 in Row 5 Column B cannot be ON so eliminate
Contradiction: No possibilities left for Value 4 in Row 7
Forcing Networks Value 8 in Row 8 Column B cannot be ON so eliminate
Contradiction: No possibilities left for Row 7 Column I
X-Cycles Value 4 of Cell I9 has weak links to both ends of the chain
This possibility would cause a contradiction - Eliminate
X-Cycles Value 3 of Cell E4 has weak links to both ends of the chain
This possibility would cause a contradiction - Eliminate

... by: Serban

# 705 Basics to 22

1. C2=4 & J8=5 solve

2. A4=F1=1 solve

3. J1=6 & J2=8 solve