Expert Star Battle answer — September 14, 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 9, column 9).
3. Blocking rule: This position would block too many candidates (row 9, column 10).
4. Three candidates with two adjacent: Isolated candidate must hold a star (row 8, column 9).
5. Mark 6 cells adjacent to stars as X (row 7, column 8).
6. Clump analysis (Region 1): candidate clumps can only just supply the remaining stars (row 5, column 9).
7. Clump analysis (Region 5): candidate clumps can only just supply the remaining stars (row 9, column 5).
8. Clump analysis (Region 7): candidate clumps can only just supply the remaining stars (row 8, column 3).
9. Clump analysis (Region 9): candidate clumps can only just supply the remaining stars (row 5, column 7).
10. Generalized counting (rows 10-10): region star limits exclude these cells (row 10, column 1).
11. Generalized counting (columns 9-10): region star limits exclude these cells (row 1, column 9).
12. Composite container (columns 1-8): Regions 2, 3, 5, 6, 7, 9 and 10 are confined here, so the leftover cells owe exactly 2 of the band's 16 stars - a star on these cells would crowd them out (row 3, column 7).
13. Lookahead: Placing star here leads to contradiction - row 10 can only hold 2 stars but the regions there would be forced to place 3 (row 8, column 7).
14. Three candidates with two adjacent: Isolated candidate must hold a star (row 7, column 7).
15. Mark 3 cells adjacent to stars as X (row 6, column 6).
16. Three candidates with two adjacent: Isolated candidate must hold a star (row 5, column 8).
17. Mark 4 cells adjacent to stars as X (row 4, column 7).
18. Region completion: 1 star needed, 1 candidate (row 6, column 10).
19. Two-option rule: Cell adjacent to both candidates (row 6, column 4).
20. Two-option rule: Cell adjacent to both candidates (row 7, column 4).
21. Blocking rule: This position would block too many candidates (row 3, column 9).
22. Clump analysis (Region 8): candidate clumps can only just supply the remaining stars (row 10, column 10).
23. Region completion: 1 star needed, 1 candidate (row 10, column 9).
24. Mark 1 cell adjacent to stars as X (row 10, column 8).
25. Column 9 complete: Mark 1 remaining cells as X (row 2, column 9).
26. Clump analysis (Row 10): each clump must supply its full share of stars (row 9, column 7).
27. Mark 3 cells adjacent to stars as X (row 9, column 6).
28. Column 7 complete: Mark 2 remaining cells as X (row 1, column 7).
29. Two-option rule: Cell adjacent to both candidates (row 9, column 4).
30. Clump analysis (Row 9): candidate clumps can only just supply the remaining stars (row 8, column 2).
31. Clump analysis (Column 6): candidate clumps can only just supply the remaining stars (row 2, column 5).
32. Clump analysis (Column 10): each clump must supply its full share of stars (row 3, column 8).
33. Mark 1 cell adjacent to stars as X (row 2, column 8).
34. Column 8 complete: Mark 1 remaining cells as X (row 1, column 8).
35. Clump analysis (Region 7): candidate clumps can only just supply the remaining stars (row 6, column 2).
36. Region completion: 1 star needed, 1 candidate (row 6, column 5).
37. Mark 3 cells adjacent to stars as X (row 5, column 4).
38. Row 6 complete: Mark 1 remaining cells as X (row 6, column 1).
39. Clump analysis (Row 5): candidate clumps can only just supply the remaining stars (row 4, column 2).
40. Clump analysis (Column 6): candidate clumps can only just supply the remaining stars (row 1, column 5).
41. Clump analysis (Region 3): candidate clumps can only just supply the remaining stars (row 3, column 3).
42. Clump analysis (Region 3): each clump must supply its full share of stars (row 4, column 6).
43. Mark 1 cell adjacent to stars as X (row 3, column 6).
44. Clump analysis (Region 6): candidate clumps can only just supply the remaining stars (row 1, column 3).
45. Two-option rule: Cell adjacent to both candidates (row 5, column 3).
46. Two last candidates (row 5): Eliminate 1 cell adjacent to both (row 4, column 1).
47. Clump analysis (Row 1): candidate clumps can only just supply the remaining stars (row 2, column 1).
48. Column completion: 1 star needed, 1 candidate (row 1, column 6).
49. Clump analysis (Row 2): candidate clumps can only just supply the remaining stars (row 3, column 10).
50. Region completion: 1 star needed, 1 candidate (row 2, column 10).
51. Crowding (Region 2): a star here would leave too little room for its 2 remaining stars (row 4, column 3).
52. Region completion: 1 star needed, 1 candidate (row 4, column 4).
53. Crowding (Column 3): a star here would leave too little room for its 2 remaining stars (row 8, column 4).
54. Row completion: 1 star needed, 1 candidate (row 8, column 5).
55. Column 5 complete: Mark 1 remaining cells as X (row 10, column 5).
56. Region completion: 1 star needed, 1 candidate (row 10, column 4).
57. Mark 1 cell adjacent to stars as X (row 9, column 3).
58. Column completion: 2 stars needed, 2 candidates (row 2, column 3).
59. Mark 3 cells adjacent to stars as X (row 1, column 2).
60. Region completion: 2 stars needed, 2 candidates (row 1, column 1).
61. Region completion: 1 star needed, 1 candidate (row 5, column 2).
62. Mark 1 cell adjacent to stars as X (row 5, column 1).
63. Row completion: 1 star needed, 1 candidate (row 3, column 1).
64. Column 1 complete: Mark 1 remaining cells as X (row 9, column 1).
65. Region completion: 1 star needed, 1 candidate (row 9, column 2).
66. Column 2 complete: Mark 1 remaining cells as X (row 7, column 2).
67. Region completion: 1 star needed, 1 candidate (row 7, column 3).
68. Solved! Every row, column, and region has its two stars, none touching.