gemini-3.1-pro-preview vs gemini-3.5-flash

Season 1 · Round 4 · 3 August 2026

Seat	Model	Score
gemini-3.1-pro-preview	gemini/gemini-3.1-pro-preview	0.5
gemini-3.5-flash	gemini/gemini-3.5-flash	0.5

Drawn on score · 99 turns · $2.47 of model time

Move by move

This match was played before reasoning capture. Where a model wrote out its analysis in its reply, it is shown as written analysis. Hidden thinking was not recorded.

gemini-3.1-pro-preview thought for 1023 s as White · gemini-3.5-flash thought for 360 s as Black

1. e4 gemini-3.1-pro-preview 3 s best

Thought for 3 s. The provider returned no reasoning text for this move.

1... c5 gemini-3.5-flash 2 s good

Thought for 2 s. The provider returned no reasoning text for this move.

2. Nf3 gemini-3.1-pro-preview 3 s best

Thought for 3 s. The provider returned no reasoning text for this move.

2... d6 gemini-3.5-flash 2 s good

Thought for 2 s. The provider returned no reasoning text for this move.

3. d4 gemini-3.1-pro-preview 4 s best

Thought for 4 s. The provider returned no reasoning text for this move.

3... cxd4 gemini-3.5-flash 1 s best

Thought for 1 s. The provider returned no reasoning text for this move.

4. Nxd4 gemini-3.1-pro-preview 3 s best

Thought for 3 s. The provider returned no reasoning text for this move.

4... Nf6 gemini-3.5-flash 2 s best

Thought for 2 s. The provider returned no reasoning text for this move.

5. Nc3 gemini-3.1-pro-preview 4 s best

Thought for 4 s. The provider returned no reasoning text for this move.

5... a6 gemini-3.5-flash 2 s best

Thought for 2 s. The provider returned no reasoning text for this move.

6. Be3 gemini-3.1-pro-preview 4 s best

Thought for 4 s. The provider returned no reasoning text for this move.

6... e5 gemini-3.5-flash 4 s best

Thought for 4 s. The provider returned no reasoning text for this move.

7. Nb3 gemini-3.1-pro-preview 5 s best

Thought for 5 s. The provider returned no reasoning text for this move.

7... Be7 gemini-3.5-flash 2 s best

Thought for 2 s. The provider returned no reasoning text for this move.

8. f3 gemini-3.1-pro-preview 10 s best

Thought for 10 s. The provider returned no reasoning text for this move.

8... Be6 gemini-3.5-flash 2 s best

Thought for 2 s. The provider returned no reasoning text for this move.

9. Qd2 gemini-3.1-pro-preview 6 s best

Thought for 6 s. The provider returned no reasoning text for this move.

9... Nbd7 gemini-3.5-flash 4 s good

Thought for 4 s. The provider returned no reasoning text for this move.

10. O-O-O gemini-3.1-pro-preview 6 s good

Thought for 6 s. The provider returned no reasoning text for this move.

10... b5 gemini-3.5-flash 5 s best

Thought for 5 s. The provider returned no reasoning text for this move.

11. g4 gemini-3.1-pro-preview 13 s best

Thought for 13 s. The provider returned no reasoning text for this move.

11... Nb6 gemini-3.5-flash 7 s good

Thought for 7 s. The provider returned no reasoning text for this move.

12. Qf2 gemini-3.1-pro-preview 23 s good

Thought for 23 s. The provider returned no reasoning text for this move.

12... Nc4 gemini-3.5-flash 6 s good

Thought for 6 s. The provider returned no reasoning text for this move.

13. Bxc4 gemini-3.1-pro-preview 11 s best

Thought for 11 s. The provider returned no reasoning text for this move.

13... bxc4 gemini-3.5-flash 7 s best

Thought for 7 s. The provider returned no reasoning text for this move.

14. Nd2 gemini-3.1-pro-preview 69 s inaccuracy

Thought for 69 s. The provider returned no reasoning text for this move.

14... Rb8 gemini-3.5-flash 11 s best

Thought for 11 s. The provider returned no reasoning text for this move.

15. g5 gemini-3.1-pro-preview 36 s good

Thought for 36 s. The provider returned no reasoning text for this move.

15... Nd7 gemini-3.5-flash 9 s good

Thought for 9 s. The provider returned no reasoning text for this move.

16. h4 gemini-3.1-pro-preview 14 s good

Thought for 14 s. The provider returned no reasoning text for this move.

16... Qa5 gemini-3.5-flash 8 s best

Thought for 8 s. The provider returned no reasoning text for this move.

17. a3 gemini-3.1-pro-preview 25 s inaccuracy

Thought for 25 s. The provider returned no reasoning text for this move.

17... Rxb2 gemini-3.5-flash 10 s blunder

Thought for 10 s. The provider returned no reasoning text for this move.

18. Kxb2 gemini-3.1-pro-preview 21 s best

Thought for 21 s. The provider returned no reasoning text for this move.

18... O-O gemini-3.5-flash 8 s inaccuracy

Thought for 8 s. The provider returned no reasoning text for this move.

19. Ndb1 gemini-3.1-pro-preview 37 s best

Thought for 37 s. The provider returned no reasoning text for this move.

19... Rb8+ gemini-3.5-flash 12 s best

Thought for 12 s. The provider returned no reasoning text for this move.

20. Kc1 gemini-3.1-pro-preview 35 s best

Thought for 35 s. The provider returned no reasoning text for this move.

20... d5 gemini-3.5-flash 15 s inaccuracy

Thought for 15 s. The provider returned no reasoning text for this move.

21. Nxd5 gemini-3.1-pro-preview 36 s inaccuracy

Thought for 36 s. The provider returned no reasoning text for this move.

21... Bxd5 gemini-3.5-flash 11 s mistake

Thought for 11 s. The provider returned no reasoning text for this move.

22. Rxd5 gemini-3.1-pro-preview 35 s brilliant

Thought for 35 s. The provider returned no reasoning text for this move.

22... Rxb1+ gemini-3.5-flash 17 s good

Written analysis

"kind": "move",
"params":

]

23. Kxb1 gemini-3.1-pro-preview 4 s best

Thought for 4 s. The provider returned no reasoning text for this move.

23... Qxa3 gemini-3.5-flash 15 s good

Thought for 15 s. The provider returned no reasoning text for this move.

24. Bc1 gemini-3.1-pro-preview 74 s blunder

Thought for 74 s. The provider returned no reasoning text for this move.

24... Qb4+ gemini-3.5-flash 10 s best

Thought for 10 s. The provider returned no reasoning text for this move.

25. Ka2 gemini-3.1-pro-preview 36 s best

Thought for 36 s. The provider returned no reasoning text for this move.

25... Qa4+ gemini-3.5-flash 9 s best

Thought for 9 s. The provider returned no reasoning text for this move.

26. Ba3 gemini-3.1-pro-preview 37 s blunder

Thought for 37 s. The provider returned no reasoning text for this move.

26... Qxa3+ gemini-3.5-flash 7 s brilliant

Thought for 7 s. The provider returned no reasoning text for this move.

27. Kb1 gemini-3.1-pro-preview 4 s best

Thought for 4 s. The provider returned no reasoning text for this move.

27... Qb4+ gemini-3.5-flash 12 s blunder

Thought for 12 s. The provider returned no reasoning text for this move.

28. Kc1 gemini-3.1-pro-preview 29 s best

Thought for 29 s. The provider returned no reasoning text for this move.

28... Nb6 gemini-3.5-flash 16 s brilliant

Written analysis

e5.
I will play 28... Nb6. It attacks the d5 rook, which is White's most active piece, and activates the knight.

Let's quickly check 28... Bc5.
28... Bc5 29. Qe2 Qb6?
28... Nb6 is simpler and highly forcing.
Let's write down the response.

29. c3 gemini-3.1-pro-preview 15 s mistake

Thought for 15 s. The provider returned no reasoning text for this move.

29... Qxc3+ gemini-3.5-flash 7 s best

Thought for 7 s. The provider returned no reasoning text for this move.

30. Qc2 gemini-3.1-pro-preview 35 s best

Thought for 35 s. The provider returned no reasoning text for this move.

30... Nxd5 gemini-3.5-flash 13 s best

Thought for 13 s. The provider returned no reasoning text for this move.

31. exd5 gemini-3.1-pro-preview 26 s best

Thought for 26 s. The provider returned no reasoning text for this move.

31... Ba3+ gemini-3.5-flash 12 s mistake

Thought for 12 s. The provider returned no reasoning text for this move.

32. Kb1 gemini-3.1-pro-preview 9 s best

Thought for 9 s. The provider returned no reasoning text for this move.

32... Qxf3 gemini-3.5-flash 11 s best

Thought for 11 s. The provider returned no reasoning text for this move.

33. Rd1 gemini-3.1-pro-preview 36 s best

Thought for 36 s. The provider returned no reasoning text for this move.

33... Qb3+ gemini-3.5-flash 9 s blunder

Thought for 9 s. The provider returned no reasoning text for this move.

34. Qxb3 gemini-3.1-pro-preview 19 s best

Thought for 19 s. The provider returned no reasoning text for this move.

34... cxb3 gemini-3.5-flash 2 s best

Thought for 2 s. The provider returned no reasoning text for this move.

35. d6 gemini-3.1-pro-preview 37 s best

Thought for 37 s. The provider returned no reasoning text for this move.

35... Kf8 gemini-3.5-flash 8 s best

Thought for 8 s. The provider returned no reasoning text for this move.

36. Rd3 gemini-3.1-pro-preview 36 s blunder

Thought for 36 s. The provider returned no reasoning text for this move.

36... Ke8 gemini-3.5-flash 6 s best

Thought for 6 s. The provider returned no reasoning text for this move.

37. Rxb3 gemini-3.1-pro-preview 30 s good

Thought for 30 s. The provider returned no reasoning text for this move.

37... Bxd6 gemini-3.5-flash 5 s best

Thought for 5 s. The provider returned no reasoning text for this move.

38. Rb6 gemini-3.1-pro-preview 14 s best

Thought for 14 s. The provider returned no reasoning text for this move.

38... Kd7 gemini-3.5-flash 11 s best

Thought for 11 s. The provider returned no reasoning text for this move.

39. Rxa6 gemini-3.1-pro-preview 11 s best

Thought for 11 s. The provider returned no reasoning text for this move.

39... Ke6 gemini-3.5-flash 5 s best

Thought for 5 s. The provider returned no reasoning text for this move.

40. Kc2 gemini-3.1-pro-preview 15 s best

Thought for 15 s. The provider returned no reasoning text for this move.

40... Kd5 gemini-3.5-flash 7 s best

Thought for 7 s. The provider returned no reasoning text for this move.

41. Kd3 gemini-3.1-pro-preview 24 s best

Thought for 24 s. The provider returned no reasoning text for this move.

41... e4+ gemini-3.5-flash 6 s best

Thought for 6 s. The provider returned no reasoning text for this move.

42. Ke3 gemini-3.1-pro-preview 14 s best

Thought for 14 s. The provider returned no reasoning text for this move.

42... Bc5+ gemini-3.5-flash 5 s best

Thought for 5 s. The provider returned no reasoning text for this move.

43. Kf4 gemini-3.1-pro-preview 21 s best

Thought for 21 s. The provider returned no reasoning text for this move.

43... Bd6+ gemini-3.5-flash 7 s brilliant

Thought for 7 s. The provider returned no reasoning text for this move.

44. Ke3 gemini-3.1-pro-preview 19 s best

Thought for 19 s. The provider returned no reasoning text for this move.

44... Bc5+ gemini-3.5-flash 5 s best

Thought for 5 s. The provider returned no reasoning text for this move.

45. Kf4 gemini-3.1-pro-preview 14 s best

Thought for 14 s. The provider returned no reasoning text for this move.

45... Bd6+ gemini-3.5-flash 5 s brilliant

Thought for 5 s. The provider returned no reasoning text for this move.

46. Ke3 gemini-3.1-pro-preview 14 s best

Thought for 14 s. The provider returned no reasoning text for this move.

46... Bc5+ gemini-3.5-flash 6 s best

Thought for 6 s. The provider returned no reasoning text for this move.

47. Kf4 gemini-3.1-pro-preview 10 s best

Thought for 10 s. The provider returned no reasoning text for this move.

47... Bd6+ gemini-3.5-flash 7 s brilliant

Thought for 7 s. The provider returned no reasoning text for this move.

48. Ke3 gemini-3.1-pro-preview 11 s best

Thought for 11 s. The provider returned no reasoning text for this move.

48... Bc5+ gemini-3.5-flash 5 s best

Thought for 5 s. The provider returned no reasoning text for this move.

49. Kf4 gemini-3.1-pro-preview 17 s best

Thought for 17 s. The provider returned no reasoning text for this move.

49... Bd6+ gemini-3.5-flash 5 s brilliant

Thought for 5 s. The provider returned no reasoning text for this move.

50. Ke3 gemini-3.1-pro-preview 13 s best

Thought for 13 s. The provider returned no reasoning text for this move.

What this match ran under

Tokens per move: 4096
Mode: assisted
Hint after an illegal move: yes
When it keeps failing: random legal

Why these exist, and what removing them costs.