Expert Star Battle answer — September 12, 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 2, column 5).
3. Blocking rule: This position would block too many candidates (row 3, column 8).
4. Blocking rule: This position would block too many candidates (row 3, column 9).
5. Three candidates with two adjacent: Isolated candidate must hold a star (row 2, column 9).
6. Mark 6 cells adjacent to stars as X (row 1, column 8).
7. Two-option rule: Cell adjacent to both candidates (row 5, column 8).
8. Two-option rule: Cell adjacent to both candidates (row 5, column 9).
9. Clump analysis (Region 5): candidate clumps can only just supply the remaining stars (row 1, column 5).
10. Generalized counting (columns 9-10): region star limits exclude these cells (row 8, column 9).
11. Region completion: 1 star needed, 1 candidate (row 4, column 8).
12. Mark 3 cells adjacent to stars as X (row 3, column 7).
13. Clump analysis (Column 7): candidate clumps can only just supply the remaining stars (row 7, column 6).
14. Squeeze (columns 7-8): the band's clumps can only just fit its stars (row 7, column 7).
15. Composite container (rows 5-10): Regions 2, 6, 7 and 9 are confined here, so the leftover cells owe exactly 4 of the band's 12 stars - a star on these cells would crowd them out (row 4, column 2).
16. Composite container (rows 6-10): Regions 2, 6, 7 and 9 are confined here, so the leftover cells owe exactly 2 of the band's 10 stars - a star on these cells would crowd them out (row 7, column 4).
17. Composite container (columns 6-8): Region 6 is confined here, so the leftover cells owe exactly 3 of the band's 6 stars - a star on these cells would crowd them out (row 3, column 5).
18. Clump analysis (Region 5): candidate clumps can only just supply the remaining stars (row 2, column 3).
19. Clump analysis (Region 4): candidate clumps can only just supply the remaining stars (row 4, column 1).
20. Lookahead: Placing star here leads to contradiction - Region 6 would end up with more than 2 stars (row 8, column 8).
21. Squeeze (columns 7-8): each clump in the band must supply its full share of stars (row 8, column 7).
22. Mark 1 cell adjacent to stars as X (row 8, column 6).
23. Clump analysis (Column 5): candidate clumps can only just supply the remaining stars (row 8, column 4).
24. Clump analysis (Column 4): candidate clumps can only just supply the remaining stars (row 4, column 3).
25. Squeeze (rows 9-10): the band's clumps can only just fit its stars (row 7, column 5).
26. Clump analysis (Column 5): candidate clumps can only just supply the remaining stars (row 5, column 4).
27. Clump analysis (Column 4): candidate clumps can only just supply the remaining stars (row 1, column 3).
28. Clump analysis (Column 3): candidate clumps can only just supply the remaining stars (row 5, column 2).
29. Crowding (Column 2): a star here would leave too little room for its 2 remaining stars (row 2, column 1).
30. Generalized counting (rows 7-10): region star limits exclude these cells (row 6, column 9).
31. Generalized counting (columns 1-5): region star limits exclude these cells (row 4, column 6).
32. Three candidates in a column: Middle cell can't hold a star (row 2, column 6).
33. Column completion: 2 stars needed, 2 candidates (row 1, column 6).
34. Column completion: 1 star needed, 1 candidate (row 3, column 6).
35. Generalized counting (rows 1-3): region star limits exclude these cells (row 3, column 2).
36. Three candidates with two adjacent: Isolated candidate must hold a star (row 5, column 1).
37. Clump analysis (Column 2): candidate clumps can only just supply the remaining stars (row 1, column 1).
38. Clump analysis (Column 2): each clump must supply its full share of stars (row 9, column 2).
39. Mark 4 cells adjacent to stars as X (row 8, column 1).
40. Region completion: 1 star needed, 1 candidate (row 7, column 1).
41. Row completion: 1 star needed, 1 candidate (row 8, column 10).
42. Mark 4 cells adjacent to stars as X (row 7, column 9).
43. Row completion: 1 star needed, 1 candidate (row 7, column 3).
44. Mark 1 cell adjacent to stars as X (row 6, column 3).
45. Row completion: 1 star needed, 1 candidate (row 9, column 5).
46. Mark 1 cell adjacent to stars as X (row 10, column 5).
47. Column 1 complete: Mark 1 remaining cells as X (row 3, column 1).
48. Row completion: 1 star needed, 1 candidate (row 3, column 4).
49. Mark 2 cells adjacent to stars as X (row 2, column 4).
50. Region completion: 1 star needed, 1 candidate (row 5, column 3).
51. Row completion: 1 star needed, 1 candidate (row 2, column 2).
52. Mark 1 cell adjacent to stars as X (row 1, column 2).
53. Region completion: 1 star needed, 1 candidate (row 1, column 4).
54. Row completion: 1 star needed, 1 candidate (row 4, column 10).
55. Mark 1 cell adjacent to stars as X (row 5, column 10).
56. Region complete: Mark 1 remaining cells as X (row 6, column 10).
57. Row 5 complete: Mark 1 remaining cells as X (row 5, column 5).
58. Region completion: 1 star needed, 1 candidate (row 6, column 5).
59. Column completion: 1 star needed, 1 candidate (row 10, column 9).
60. Mark 2 cells adjacent to stars as X (row 10, column 8).
61. Row completion: 1 star needed, 1 candidate (row 10, column 7).
62. Column 7 complete: Mark 1 remaining cells as X (row 6, column 7).
63. Region completion: 1 star needed, 1 candidate (row 6, column 8).
64. Solved! Every row, column, and region has its two stars, none touching.