Expert Star Battle answer — August 7, 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 8, column 9).
3. Blocking rule: This position would block too many candidates (row 9, column 9).
4. Three candidates with two adjacent: Isolated candidate must hold a star (row 9, column 8).
5. Mark 6 cells adjacent to stars as X (row 8, column 7).
6. Clump analysis (Region 5): candidate clumps can only just supply the remaining stars (row 3, column 8).
7. Lookahead: Placing star here leads to contradiction - columns 1-4 must hold 8 stars but the regions there could only supply 7 (row 2, column 3).
8. Joint analysis (Region 7 + Column 5): every legal combination of their stars rules these cells out (row 10, column 5).
9. Generalized counting (columns 1-5): region star limits exclude these cells (row 3, column 6).
10. Clump analysis (Region 7): candidate clumps can only just supply the remaining stars (row 7, column 4).
11. Crowding (Column 6): a star here would leave too little room for its 2 remaining stars (row 9, column 5).
12. Joint analysis (Column 6 + Column 7): every legal combination of their stars rules these cells out (row 2, column 8).
13. Squeeze (columns 8-9): the band's clumps can only just fit its stars (row 2, column 10).
14. Joint analysis (Region 7 + Column 6): every legal combination of their stars rules these cells out (row 5, column 5).
15. Joint analysis (Column 8 + Region 9): every legal combination of their stars rules these cells out (row 6, column 9).
16. Triple analysis (Region 8 + Region 5 + Region 9): every legal combination of their stars rules these cells out (row 5, column 7).
17. Clump analysis (Region 7): candidate clumps can only just supply the remaining stars (row 8, column 4).
18. Clump analysis (Region 10): candidate clumps can only just supply the remaining stars (row 7, column 2).
19. Deep lookahead: Placing star here leads to contradiction - column 1 can only hold 2 stars but the regions there would be forced to place 3 (row 2, column 4).
20. Deep lookahead: Placing star here leads to contradiction - Region 1 would end up with more than 2 stars (row 3, column 2).
21. Deep lookahead: Placing star here leads to contradiction - Region 4 would end up with more than 2 stars (row 3, column 3).
22. Deep lookahead: Placing star here leads to contradiction - Row 3 would only have room for 1 of the 2 stars it still needs (row 4, column 5).
23. Deep lookahead: Placing star here leads to contradiction - Row 6 would only have room for 0 of the 1 star it still needs (row 4, column 8).
24. Triple analysis (Column 8 + Column 9 + Region 9): every legal combination of their stars rules these cells out (row 5, column 10).
25. Deep lookahead: Placing star here leads to contradiction - Row 10 would end up with more than 2 stars (row 1, column 4).
26. Deep lookahead: Placing star here leads to contradiction - Row 7 would only have room for 1 of the 2 stars it still needs (row 1, column 2).
27. Deep lookahead: Placing star here leads to contradiction - stars at R9C4 and R10C4 would touch (row 3, column 5).
28. Deep lookahead: Placing star here leads to contradiction - column 1 can only hold 2 stars but the regions there would be forced to place 3 (row 3, column 7).
29. Three candidates with two adjacent: Isolated candidate must hold a star (row 6, column 6).
30. Mark 3 cells adjacent to stars as X (row 5, column 6).
31. Region completion: 1 star needed, 1 candidate (row 4, column 7).
32. Mark 1 cell adjacent to stars as X (row 5, column 8).
33. Column completion: 1 star needed, 1 candidate (row 2, column 7).
34. Three candidates with two adjacent: Isolated candidate must hold a star (row 10, column 4).
35. Mark 1 cell adjacent to stars as X (row 9, column 4).
36. Region completion: 1 star needed, 1 candidate (row 8, column 5).
37. Mark 1 cell adjacent to stars as X (row 9, column 6).
38. Column completion: 1 star needed, 1 candidate (row 10, column 6).
39. Row 10 complete: Mark 3 remaining cells as X (row 10, column 1).
40. Region completion: 1 star needed, 1 candidate (row 7, column 8).
41. Mark 2 cells adjacent to stars as X (row 6, column 8).
42. Clump analysis (Column 9): candidate clumps can only just supply the remaining stars (row 4, column 10).
43. Clump analysis (Region 10): candidate clumps can only just supply the remaining stars (row 8, column 2).
44. Composite container (rows 1-5): Regions 2, 3 and 8 are confined here, so the leftover cells owe exactly 3 of the band's 10 stars - a star on these cells would crowd them out (row 4, column 3).
45. Squeeze (rows 3-4): the band's clumps can only just fit its stars (row 5, column 4).
46. Crowding (Row 5): a star here would leave too little room for its 2 remaining stars (row 4, column 2).
47. Squeeze (rows 5-6): the band's clumps can only just fit its stars (row 5, column 2).
48. Column completion: 2 stars needed, 2 candidates (row 2, column 2).
49. Mark 4 cells adjacent to stars as X (row 1, column 1).
50. Row completion: 2 stars needed, 2 candidates (row 1, column 5).
51. Mark 1 cell adjacent to stars as X (row 2, column 5).
52. Region completion: 1 star needed, 1 candidate (row 3, column 4).
53. Mark 1 cell adjacent to stars as X (row 4, column 4).
54. Row completion: 1 star needed, 1 candidate (row 1, column 10).
55. Mark 1 cell adjacent to stars as X (row 2, column 9).
56. Row completion: 1 star needed, 1 candidate (row 3, column 9).
57. Mark 1 cell adjacent to stars as X (row 4, column 9).
58. Row completion: 1 star needed, 1 candidate (row 4, column 1).
59. Mark 1 cell adjacent to stars as X (row 5, column 1).
60. Row completion: 2 stars needed, 2 candidates (row 5, column 3).
61. Mark 1 cell adjacent to stars as X (row 6, column 3).
62. Region completion: 1 star needed, 1 candidate (row 7, column 3).
63. Mark 1 cell adjacent to stars as X (row 8, column 3).
64. Row completion: 1 star needed, 1 candidate (row 5, column 9).
65. Mark 1 cell adjacent to stars as X (row 6, column 10).
66. Region complete: Mark 1 remaining cells as X (row 7, column 10).
67. Row completion: 1 star needed, 1 candidate (row 6, column 1).
68. Mark 1 cell adjacent to stars as X (row 7, column 1).
69. Column 1 complete: Mark 2 remaining cells as X (row 8, column 1).
70. Region completion: 1 star needed, 1 candidate (row 9, column 2).
71. Row completion: 1 star needed, 1 candidate (row 8, column 10).
72. Mark 1 cell adjacent to stars as X (row 9, column 10).
73. Solved! Every row, column, and region has its two stars, none touching.