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