... by: Envy E

-4 G5 +4 C5 ( +4 E1 ) +1 A6 +1 B1 +59 C1 F1 +26 G1 H1 H5 +8 G5

+2 or +6 at G5 create a Unique Rectangle

... by: Envy E

Begin where Solver runs out of known solutions

+3 B9 +2 A8 +5 A7 +3 A2 +3 F3 +3 E7 +7 G7 +3 H8 +3 B6 -3 B9

... by: Frans Goosens

#663

Combination 2-digits cells

A3=1 No solution, Undo calculation
A3=4 Wrong, Undo calculation
A3=1 No solution, Fixed
A8=2 No solution, Undo calculation
A8=3 Wrong, Undo calculation
A8=2 No solution, Fixed
A2=3 Wrong, Undo calculation
A2=5 ( I8=6 ) Solved,

Total solving time is : 135 sec.
Number of logical steps is : 16352

... by: Serban

# 663 A4=6 Basics to 23

@ Dieter thank you F9=H8=3 OR F9=G4=3 solve

1. Number 2 n=2 e=7 N=29 Nc=44 Ns=44 => B2=G7=2 solve

2. Number 5 n=2 e=7 N=26 Nc=25 Ns=14 =>
-- 2a. B7=5 basics to 50 => XY-Wing-379 [FH6,H8] => F8 <>7 = > F8=8 solve
--- 2b. A2=J3=5 solve

3. Number 9 n=2 e=7 N=28 Nc=33 Ns=3 => B1=J2=9 solve
Note : E4=H6=9

... by: Dieter

@Yves
For me "solves" means you can solve the puzzle with basic logic steps like single cells, hidden pairs, triplets, quadruplets, x-chain. No try and error needed anymore.

... by: Yves

F9=H8=3

... by: Dieter

@Serban:
F9=H7=3 >> H7 is preset with 8

... by: Dieter

#663 - initially populated cells: 22 = 27,2%
No solver used.
basics: A4 = 6
populated cells: 23 = 28,4%
Strategy: Numbers 6,1,4,7 occur most frequently, combine two cells.
combinations of E5 = (1,6,8) and E7 = (3,4,7,9)
4 matrices left after basic checks: E5/E7 = 1/3, 8/3, 1/7 and 8/7
E5/E7 = 8/7 solve with C4=8

Review:
C4=8 & E7=7 solve.

... by: Serban

# 663 A4=6 Basics to 23

1. Number 3 n=2 e=7 N=24 Nc=14 Ns=14 => F9=H7=3 OR F9=G4=3solve

2. Column 4 n=3 e=6 Nc=18 Ns=4=> B4=7 & C4=8 solve
Note: D4=5 => F5=2

... by: Yves

B6=3 & B7=5 solve

I'm asking the community what the word "solve" means.

A puzzle is said to be solved when the successive steps leading to the solution are basic singletons (cells or groups).
Do you agree ?