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⚫ Gomoku-Lite · Perfect-information game · round-robin · 1957 games · board 9×9
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How Gomoku-Lite works

A two-player game on a 9×9 board (columns A–I, rows 1–9). The two models alternate placing one stone of their own color on any empty cell:
Free-style Gomoku — no forbidden-move restrictions — and like Connect Four there's no hidden information or chance, so we score tactical accuracy: did the model complete an available five (win-take) and block the opponent's immediate five-threat (block rate)?
What the model sees each turn: the full current board, whose turn it is, and that any empty cell is a legal move — perfect information.

1 · Results — who won

#ModelEloNet/gameWin% 1st-move win%2nd-move win%Gamestokens/dec$/1K dec
1GPT 5.5 1686
±22
+0.38 68% 83% 53% 262
2Kimi K2.6 1657
±21
+0.37 69% 78% 59% 345 16,740$66.96
3GLM-5.1 1603
±18
+0.23 61% 64% 58% 379 8,268$36.38
4GLM-5.2 1596
±19
+0.19 59% 65% 53% 299 16,574$72.93
5GPT 5.4 1593
±22
+0.12 55% 65% 45% 257
6DeepSeek V4 Pro 1573
±19
+0.16 58% 63% 52% 363 9,888$34.41
7Claude Opus 4.8 1529
±16
+0.08 53% 67% 42% 464
8Claude Sonnet 4.6 1510
±17
+0.00 50% 58% 43% 495
9Qwen3.7 Plus 1444
±20
-0.24 38% 43% 32% 300 11,609$18.57
10MiniMax-M3 1344
±22
-0.46 27% 35% 19% 310 13,510$16.21
11GPT-OSS 120B 1243
±28
-0.63 18% 24% 12% 290 2,420$1.45
12MiniMax-M2.7 1220
±37
-0.65 17% 25% 9% 150 13,232$15.88
columns: Elo opponent-adjusted rating · net/game mean result/game (+1/−1/0) · win% games won · 1st-move win% / 2nd-move win% win rate moving first / second · games games played (varies by wave)

Elo rating

Whiskers show ±1 bootstrap SD (resampling games 300×) — wider bars mean fewer/less-decisive games, so ratings within a whisker of each other are a near tie.

Win / draw / loss

⚔️ Head-to-head (row wins–losses vs column)

Claude Opus 4.8Claude Sonnet 4.6DeepSeek V4 ProGLM-5.1GLM-5.2GPT 5.4GPT 5.5GPT-OSS 120BKimi K2.6MiniMax-M2.7MiniMax-M3Qwen3.7 Plus
Claude Opus 4.824-26
0d
27-38
0d
26-39
0d
22-8
0d
16-14
0d
8-20
2d
39-11
0d
6-28
0d
43-7
0d
23-7
0d
14-14
2d
Claude Sonnet 4.626-24
0d
25-40
0d
31-34
0d
12-17
1d
14-15
1d
4-26
0d
41-8
1d
15-50
0d
38-12
0d
20-10
0d
20-10
0d
DeepSeek V4 Pro38-27
0d
40-25
0d
14-16
0d
10-20
0d
9-10
0d
8-16
0d
24-6
0d
15-15
0d
9-1
0d
21-9
0d
22-8
0d
GLM-5.139-26
0d
34-31
0d
16-14
0d
12-17
0d
15-15
0d
12-17
1d
29-1
0d
14-16
0d
9-1
0d
27-3
0d
25-5
0d
GLM-5.28-22
0d
17-12
1d
20-10
0d
17-12
0d
13-16
1d
8-21
1d
28-2
0d
14-16
0d
0-0
0d
27-3
0d
24-6
0d
GPT 5.414-16
0d
15-14
1d
10-9
0d
15-15
0d
16-13
1d
14-16
0d
0-0
0d
10-18
0d
0-0
0d
24-6
0d
24-5
1d
GPT 5.520-8
2d
26-4
0d
16-8
0d
17-12
1d
21-8
1d
16-14
0d
0-0
0d
18-10
0d
0-0
0d
23-7
0d
22-8
0d
GPT-OSS 120B11-39
0d
8-41
1d
6-24
0d
1-29
0d
2-28
0d
0-0
0d
0-0
0d
1-29
0d
6-4
0d
12-18
0d
6-24
0d
Kimi K2.628-6
0d
50-15
0d
15-15
0d
16-14
0d
16-14
0d
18-10
0d
10-18
0d
29-1
0d
10-0
0d
26-4
0d
19-11
0d
MiniMax-M2.77-43
0d
12-38
0d
1-9
0d
1-9
0d
0-0
0d
0-0
0d
0-0
0d
4-6
0d
0-10
0d
1-9
0d
0-0
0d
MiniMax-M37-23
0d
10-20
0d
9-21
0d
3-27
0d
3-27
0d
6-24
0d
7-23
0d
18-12
0d
4-26
0d
9-1
0d
8-22
0d
Qwen3.7 Plus14-14
2d
10-20
0d
8-22
0d
5-25
0d
6-24
0d
5-24
1d
8-22
0d
24-6
0d
11-19
0d
0-0
0d
22-8
0d

2 · Why — what decides win & loss

Tactical accuracy (win-take / block %)

Error rate by game phase

🛡️ Defense, not offense, decides games

Completing an available five (win-take) is near-saturated for everyone — it doesn't separate the field. The spread is all in defense (blocking the opponent's immediate five-threat) and in late-game errors: every model plays the opening cleanly, so skill is just not collapsing once threats pile up. Gomoku's bigger 9×9 board makes defense harder, so block% sits lower than in Connect Four across the board.
modelwin-take %block %late-game error %
GLM-5.2927024
Kimi K2.61007419
GLM-5.1946731
DeepSeek V4 Pro1006332
Claude Sonnet 4.6976141
Claude Opus 4.8905843
Qwen3.7 Plus935351
MiniMax-M3924960
GPT-OSS 120B864765
MiniMax-M2.7904770
win-take clusters at 86–100% (offense solved); block% and late-game error % fan out across the whole field and track the Elo order almost monotonically. Claude is the standout anomaly — strong in Connect Four but its late-game error rate balloons to ~43% here on the sparse 9×9 board.

🎯 The decisive test: miss-rate by threat axis

Boards are sent as space-separated text, read row by row ( X . O . .). The cost of this format is flattening a 2-D grid into a 1-D line of text: a horizontal line is contiguous in the text; a vertical line is strided across rows; a diagonal is scattered furthest. Miss-rate climbs in exactly that order. (Single, blockable immediate-loss threats only; unblockable double threats excluded.)
threat axisfacedmissedmiss-rate
horizontal (contiguous in text)428245.6%
vertical (strided across rows)4014912.2%
diagonal ↘ (down-right)2844315.1%
diagonal ↙ (down-left)2315624.2%
diagonal (both)5159919.2%
all axes134417212.8%
Horizontal threats — laid out contiguously in the text — are the easiest to defend (5.6%), while ↙ diagonals are missed 4× as often (24.2%). This points to 2-D spatial reconstruction from row-major text as the bottleneck. The effect is sharper here than in Connect Four: the 9×9 gravity-free board leans entirely on reading lines out of the text.

↘ vs ↙ : why the two diagonals differ

The game is left-right symmetric, so an asymmetry between the two diagonals can't come from the rules — it must come from the text representation. Following a diagonal means tracking a row and a column index together: the ↘ main diagonal increments both indices in lockstep and flows with the top-to-bottom, left-to-right reading order; the ↙ anti-diagonal increments the row but decrements the column — two counters moving in opposite directions, against the reading gradient — so it's missed more.
model↘ down-right↙ down-left
Claude Opus 4.821% n=6334% n=47
Claude Sonnet 4.610% n=5212% n=43
DeepSeek V4 Pro6% n=3225% n=28
GPT-OSS 120B23% n=3030% n=23
MiniMax-M2.715% n=2729% n=24
Kimi K2.616% n=3226% n=19
GLM-5.112% n=2514% n=21
MiniMax-M320% n=1042% n=12
Pooled over both games: ↘ 13.3% vs ↙ 19.0% (z=2.65, p=0.004). The direction is unanimous in Gomoku — every one of the eight models above misses ↙ more than ↘ — which is strong evidence the asymmetry is systematic, not noise.

3 · Analysis

Game-length distribution (plies)

🗺️ Move-location heatmap

Where each model places pieces (brighter = more frequent). Reveals center-control bias and opening preferences.
Claude Opus 4.8
Claude Sonnet 4.6
DeepSeek V4 Pro
GLM-5.1
GLM-5.2
GPT 5.4
GPT 5.5
GPT-OSS 120B
Kimi K2.6
MiniMax-M2.7
MiniMax-M3
Qwen3.7 Plus