ironmanor vs FlightlessPterodactyl

How it swung

The one slip

15...♖e8 cost 1.8 pawns. ♘f4 would have held it.

That walks into 16.♗b5: the queen on d1 gets a clear line, and the knight on d5 sits at the end of it.

The score

1. 1. e4 d6
2. 2. Nf3 Nf6
3. 3. Nc3 g6
4. 4. Bc4 Bg7
5. 5. O-O O-O
6. 6. d4 Nxe4
7. 7. Nxe4 d5
8. 8. Bd3 dxe4
9. 9. Bxe4 Nd7
10. 10. Bf4 c5
11. 11. c3 Nf6
12. 12. Bd3 cxd4
13. 13. Nxd4 Nd5
14. 14. Bg3 e5
15. 15. Nf3 Re8
16. 16. Bb5 Rf8
17. 17. Nxe5 Be6
18. 18. Nd7 Bxd7
19. 19. Qxd5 Bxb5
20. 20. Qxb5 Qc8
21. 21. Rfe1 a6
22. 22. Qb6 Qd7
23. 23. Rad1 Rfe8
24. 24. h4 Rxe1+
25. 25. Rxe1 h5
26. 26. Qc7 Rd8
27. 27. Qxd7 Rxd7
28. 28. Re8+ Kh7
29. 29. Bf4 Rd1+
30. 30. Kh2 Ra1
31. 31. a3 Ra2
32. 32. Bc1 Ra1
33. 33. Bg5 Ra2
34. 34. Bc1 Ra1
35. 35. Be3 Rb1
36. 36. Re7 Kg8
37. 37. Rxb7 Be5+
38. 38. g3 Bxc3
39. 39. b3 a5
40. 40. Rb8+ Kg7
41. 41. a4 Rb2
42. 42. Kg2 Be5
43. 43. Kf3 Bxb8