Expert Star Battle answer — August 21, 2026

Full written solution

Every deduction from the walkthrough above, in order. Each technique is explained in the Star Battle strategy guide.

1. Starting position — the grid is split into regions (bold outlines). Each row, column, and region needs exactly two stars, and no two stars may touch.
2. Blocking rule: This position would block too many candidates (row 5, column 3).
3. Blocking rule: This position would block too many candidates (row 2, column 9).
4. Clump analysis (Region 2): candidate clumps can only just supply the remaining stars (row 9, column 7).
5. Clump analysis (Region 4): candidate clumps can only just supply the remaining stars (row 7, column 9).
6. Clump analysis (Region 5): candidate clumps can only just supply the remaining stars (row 3, column 2).
7. Clump analysis (Region 7): candidate clumps can only just supply the remaining stars (row 2, column 4).
8. Clump analysis (Region 9): candidate clumps can only just supply the remaining stars (row 4, column 9).
9. Clump analysis (Region 10): candidate clumps can only just supply the remaining stars (row 9, column 2).
10. Undercounting: 2 regions fit in rows 9-10, eliminate 4 outside candidates (row 9, column 1).
11. Crowding (Row 9): a star here would leave too little room for its 2 remaining stars (row 8, column 9).
12. Generalized counting (rows 1-4): region star limits exclude these cells (row 4, column 4).
13. Composite container (rows 5-8): Regions 1, 3 and 4 are confined here, so the leftover cells owe exactly 2 of the band's 8 stars - a star on these cells would crowd them out (row 6, column 1).
14. Joint analysis (Row 9 + Region 4): every legal combination of their stars rules these cells out (row 6, column 9).
15. Deep lookahead: Placing star here leads to contradiction - stars at R2C7 and R3C8 would touch (row 1, column 2).
16. Deep lookahead: Placing star here leads to contradiction - Column 9 would only have room for 1 of the 2 stars it still needs (row 1, column 7).
17. Deep lookahead: Placing star here leads to contradiction - stars at R2C7 and R3C8 would touch (row 2, column 2).
18. Deep lookahead: Placing star here leads to contradiction - stars at R4C2 and R5C1 would touch (row 2, column 3).
19. Joint analysis (Region 8 + Column 1): every legal combination of their stars rules these cells out (row 7, column 1).
20. Joint analysis (Column 2 + Region 8): every legal combination of their stars rules these cells out (row 7, column 3).
21. Joint analysis (Region 1 + Row 8): every legal combination of their stars rules these cells out (row 8, column 5).
22. Quad analysis (Region 5 + Row 7 + Row 6 + Region 3): every legal combination of their stars rules these cells out (row 5, column 5).
23. Composite container (columns 1-6): Regions 1, 5, 7, 8 and 10 are confined here, so the leftover cells owe exactly 2 of the band's 12 stars - a star on these cells would crowd them out (row 4, column 7).
24. Deep lookahead: Placing star here leads to contradiction - Row 4 would only have room for 0 of the 1 star it still needs (row 2, column 8).
25. Lookahead: Placing star here leads to contradiction - row 1 can only hold 2 stars but the regions there would be forced to place 3 (row 3, column 7).
26. Deep lookahead: Placing star here leads to contradiction - stars at R3C4 and R4C3 would touch (row 1, column 6).
27. Deep lookahead: Placing star here leads to contradiction - Row 7 would only have room for 0 of the 1 star it still needs (row 2, column 10).
28. Crowding (Row 2): a star here would leave too little room for its 2 remaining stars (row 3, column 6).
29. Star claim: Region 6 must place a star in row 4; cells touching all its options are eliminated (row 5, column 7).
30. Generalized counting (rows 4-4): region star limits exclude these cells (row 4, column 1).
31. Deep lookahead: Placing star here leads to contradiction - Region 4 would only have room for 0 of the 1 star it still needs (row 3, column 5).
32. Deep lookahead: Placing star here leads to contradiction - Region 4 would only have room for 0 of the 1 star it still needs (row 1, column 5).
33. Deep lookahead: Placing star here leads to contradiction - Row 10 would end up with more than 2 stars (row 3, column 4).
34. Deep lookahead: Placing star here leads to contradiction - Region 6 would only have room for 0 of the 1 star it still needs (row 1, column 1).
35. Deep lookahead: Placing star here leads to contradiction - Region 5 would end up with more than 2 stars (row 1, column 4).
36. Three candidates with two adjacent: Isolated candidate must hold a star (row 1, column 3).
37. Squeeze (columns 4-5): the band's clumps can only just fit its stars (row 2, column 6).
38. Region completion: 1 star needed, 1 candidate (row 2, column 5).
39. Clump analysis (Column 6): candidate clumps can only just supply the remaining stars (row 7, column 5).
40. Squeeze (columns 4-5): the band's clumps can only just fit its stars (row 8, column 3).
41. Triple analysis (Region 8 + Column 3 + Region 5): every legal combination of their stars rules these cells out (row 6, column 3).
42. Column completion: 1 star needed, 1 candidate (row 10, column 5).
43. Mark 1 cell adjacent to stars as X (row 10, column 4).
44. Generalized counting (columns 1-4): region star limits exclude these cells (row 8, column 6).
45. Clump analysis (Column 6): candidate clumps can only just supply the remaining stars (row 6, column 7).
46. Crowding (Column 7): a star here would leave too little room for its 2 remaining stars (row 9, column 8).
47. Clump analysis (Row 9): candidate clumps can only just supply the remaining stars (row 8, column 10).
48. Region completion: 1 star needed, 1 candidate (row 9, column 3).
49. Mark 2 cells adjacent to stars as X (row 8, column 2).
50. Three candidates in a column: Middle cell can't hold a star (row 6, column 4).
51. Region completion: 2 stars needed, 2 candidates (row 4, column 2).
52. Mark 2 cells adjacent to stars as X (row 3, column 1).
53. Region completion: 1 star needed, 1 candidate (row 5, column 4).
54. Region completion: 2 stars needed, 2 candidates (row 2, column 1).
55. Region completion: 1 star needed, 1 candidate (row 6, column 2).
56. Mark 1 cell adjacent to stars as X (row 7, column 2).
57. Region completion: 2 stars needed, 2 candidates (row 7, column 4).
58. Region completion: 1 star needed, 1 candidate (row 8, column 1).
59. Row 2 complete: Mark 1 remaining cells as X (row 2, column 7).
60. Column completion: 2 stars needed, 2 candidates (row 8, column 7).
61. Mark 3 cells adjacent to stars as X (row 7, column 6).
62. Row completion: 1 star needed, 1 candidate (row 7, column 10).
63. Mark 1 cell adjacent to stars as X (row 6, column 10).
64. Column completion: 1 star needed, 1 candidate (row 10, column 7).
65. Mark 1 cell adjacent to stars as X (row 10, column 8).
66. Three candidates in a row: Middle cell can't hold a star (row 3, column 9).
67. Row completion: 2 stars needed, 2 candidates (row 3, column 8).
68. Mark 1 cell adjacent to stars as X (row 4, column 8).
69. Region completion: 2 stars needed, 2 candidates (row 1, column 8).
70. Mark 1 cell adjacent to stars as X (row 1, column 9).
71. Region completion: 1 star needed, 1 candidate (row 4, column 6).
72. Mark 1 cell adjacent to stars as X (row 5, column 6).
73. Row 1 complete: Mark 1 remaining cells as X (row 1, column 10).
74. Region completion: 1 star needed, 1 candidate (row 3, column 10).
75. Column completion: 1 star needed, 1 candidate (row 6, column 6).
76. Region complete: Mark 2 remaining cells as X (row 5, column 8).
77. Column completion: 2 stars needed, 2 candidates (row 5, column 9).
78. Mark 1 cell adjacent to stars as X (row 5, column 10).
79. Column completion: 1 star needed, 1 candidate (row 9, column 9).
80. Mark 1 cell adjacent to stars as X (row 9, column 10).
81. Solved! Every row, column, and region has its two stars, none touching.