Cluemaster

Introducing Cluemaster 1.0

A 3B Codenames spymaster.

Cluemaster 1.0 plays the spymaster in Codenames. It reads the board and gives your team one word and a number, aimed at as many of your words as it can reach safely, and away from the opponent's words, the neutral ones and the assassin.

It scores 60% on Cluebench, against 20% for the next best 3 to 4B model, and gives a legal clue on the first try 96% of the time.

Spymaster quality

Cluebench rates every clue good, ok or bad in a blind rating. Fresh boards, midgame and endgame are scored separately and averaged, so the mix of boards cannot move a score.

Cluebench

mean of the three board types

Cluemaster 1.060%
Phi-4 Mini 3.8B20%
Granite 4.1 3B20%
Ministral 3 3B5%
Qwen 3.5 4B3%

By board type

Cluemaster leads on every board type. Midgame, with 4 or more of your words left, is its weakest at 40, against 72 on fresh boards and 67 on endgames.

Fresh boards

Cluebench score

Cluemaster 1.072%
Phi-4 Mini 3.8B33%
Granite 4.1 3B22%
Ministral 3 3B7%
Qwen 3.5 4B0%

Midgame

Cluebench score

Cluemaster 1.040%
Granite 4.1 3B16%
Phi-4 Mini 3.8B11%
Qwen 3.5 4B9%
Ministral 3 3B3%

Endgame

Cluebench score

Cluemaster 1.067%
Granite 4.1 3B23%
Phi-4 Mini 3.8B16%
Ministral 3 3B5%
Qwen 3.5 4B1%

Legal clues

A clue is illegal if it is a board word, a root of one, or a word that contains one. Cluemaster's single answers were legal on the first try 96% of the time, against 25 to 76% for the other models.

Legal on the first try

single answer, no retry

Cluemaster 1.096%
Granite 4.1 3B76%
Phi-4 Mini 3.8B63%
Ministral 3 3B61%
Qwen 3.5 4B25%

Rated good

legal and rated good

Cluemaster 1.044%
Phi-4 Mini 3.8B17%
Qwen 3.5 4B13%
Granite 4.1 3B12%
Ministral 3 3B5%

Acceptable

legal and rated good or ok

Cluemaster 1.068%
Phi-4 Mini 3.8B34%
Granite 4.1 3B33%
Ministral 3 3B19%
Qwen 3.5 4B17%

The Studio can also ask for several clues and drop any that break the rules before choosing. With that check on, Cluemaster gave a legal clue on every held-out board it was tested on.

Speed

A single answer takes about 2.5 seconds on a 6 GB graphics card. Granite 4.1 3B is faster and shorter, at 0.6 seconds and 19 tokens per answer. The model's own answer includes a short brainstorm before the clue, which is where the extra tokens go.

Seconds per board

lower is faster

Granite 4.1 3B0.6 s
Phi-4 Mini 3.8B1.4 s
Qwen 3.5 4B1.9 s
Cluemaster 1.02.5 s
Ministral 3 3B2.8 s

Tokens per answer

lower is shorter

Granite 4.1 3B19
Qwen 3.5 4B29
Phi-4 Mini 3.8B33
Ministral 3 3B53
Cluemaster 1.093

Try it today

Cluemaster 1.0 is on Hugging Face as a Q4_K_M GGUF (2.1 GB). It needs about 3 GB of free memory and loads in Ollama, llama.cpp and LM Studio. For Ollama, put this Modelfile next to the file and run ollama create cluemaster -f Modelfile.

FROM ./cluemaster-1.0-Q4_K_M.gguf
TEMPLATE """{{ if .System }}<s>[SYSTEM_PROMPT]{{ .System }}[/SYSTEM_PROMPT]{{ end }}{{ if .Prompt }}[INST]{{ .Prompt }}[/INST]{{ end }}{{ .Response }}</s>"""
PARAMETER stop <s>
PARAMETER stop [INST]
PARAMETER temperature 0.3
PARAMETER num_ctx 4096

How to use it

The easy way: use Cluemaster Studio. Type in the board, press Get clue, and it handles the prompt and checks the clue against the rules.

Running it yourself: Cluemaster isn't a chat model. It does one job: you give it a board, and it gives you a clue.

Recommended system message

You are a Codenames spymaster. Your teammate can see every word on the board but does not know which ones are yours. You give a one-word clue and a number: the number is how many of your team's words the clue points to.

The clue must not be a word on the board, or a form or part of one. Avoid clues that could lead your teammate to the opponent's words, the neutral words, or the assassin.

Recommended user message

Put your own words in capitals.

BOARD
My team: BUNK, CENTER, BAND, SNAKE
Opponent: MAKEUP
Neutral: WELL, KITCHEN, STATE, HORSE
Assassin: MICROWAVE

Give a clue that connects 1 to 4 of your team's words. Connect 2 or 3 when there is a real link between them. If the words you have left have no good link, give a clue for a single word instead of forcing a weak pair.

Reply with your clue, the number, and the team words it connects, like this:
Clue: <one word>
Number: <how many team words it connects>
Words: <those team words, separated by commas>

What you get back

Brainstorm:
- RUBBER: BAND, SNAKE. Found 2 of 2. Risk: WELL (neutral).
Clue: RUBBER
Number: 2
Words: BAND, SNAKE

Use the Clue, Number and Words lines. The brainstorm above them is its working. Set the temperature to about 0.3 and stop after 400 tokens, because it can keep writing extra answers after the first.

It only gives clues, so any other message gets a clue back.

Model card

Model information

Description
Cluemaster 1.0 is a 3.4 billion parameter model that plays the Codenames spymaster.
Model dependencies
A LoRA fine-tune of Ministral 3 3B Instruct. Rank 16, alpha 32, on all attention and MLP layers, 24.7 million trainable parameters.
Inputs
A text prompt in the format it was trained on: the board and the clues so far. The harness builds the prompt.
Outputs
A brainstorm, then Clue, Number and Words. The model generates all of it, and it was trained to answer in this format.

Model data

Training dataset
2,494 examples (2,405 train, 89 validation), synthetic, built from 50 real boards and expanded into many board states. Clues were checked by simulation and by the legality check used to score the benchmark. Clues the model wrote were kept when rated good or ok, and replaced with human-written ones when bad.
Data processing
The sealed benchmark boards, and boards close to them, are kept out of training.

Implementation

Hardware
One Nvidia Tesla T4, trained in 16-bit.
Output format
GGUF, Q4_K_M, 2.1 GB.

Distribution

Channels
Hugging Face.
Requirements
About 3 GB of free memory. A 6 GB graphics card runs it fully on the GPU.

Evaluation

Approach
Cluebench v1.0. Held-out boards sealed before training, in three kinds: fresh boards, midgame (4 or more of your words left) and endgame (3 or fewer). Every model got the same board and format, one answer at temperature 0. Every clue was rated good, ok or bad in a blind rating. Cluemaster was benchmarked as the Q4_K_M file.
Results
As of October 2026.

Overall

ModelCluebenchRated goodAcceptableLegal first tryIllegalInvalidSeconds per boardTokens per answer
Cluemaster 1.060%44%68%96%4%0%2.5 s93
Phi-4 Mini 3.8B20%17%34%63%37%1%1.4 s33
Granite 4.1 3B20%12%33%76%24%2%0.6 s19
Ministral 3 3B5%5%19%61%39%6%2.8 s53
Qwen 3.5 4B3%13%17%25%75%0%1.9 s29

Acceptable is legal and rated good or ok. Illegal is a clue that breaks a rule. Invalid is a legal clue aimed at a neutral or opponent word.

Fresh boards

ModelScoreGoodAcceptableIllegal
Cluemaster 1.07245%85%5%
Phi-4 Mini 3.8B3332%47%37%
Granite 4.1 3B2212%37%25%
Ministral 3 3B78%23%45%
Qwen 3.5 4B02%5%90%

Midgame

ModelScoreGoodAcceptableIllegal
Cluemaster 1.04032%45%5%
Phi-4 Mini 3.8B115%27%36%
Granite 4.1 3B169%27%23%
Ministral 3 3B30%14%27%
Qwen 3.5 4B923%27%68%

Endgame

ModelScoreGoodAcceptableIllegal
Cluemaster 1.06754%74%3%
Phi-4 Mini 3.8B1616%29%38%
Granite 4.1 3B2316%34%24%
Ministral 3 3B57%19%38%
Qwen 3.5 4B115%18%65%

Scoring

CluePoints on its board
Good100
Ok70
Bad, or no clue0
Invalid: a target is a neutral word−10
Invalid: a target is an opponent word−15
Illegal, whatever it was rated−25

A segment scores 50% legal, 30% good and 20% acceptable, minus the penalties, never below zero. Cluebench is the mean of the three segments.

Intended usage and limitations

Intended usage
Giving clues as the spymaster in English Codenames.
Midgame
The weak spot. Cluemaster scores 40 on midgame boards against 72 on fresh boards and 67 on endgames.
Illegal clues
About 4% of single answers are illegal, mostly by being or containing a board word. The harness filters these out.
Benchmark conditions
The clues were produced with a modified version of the harness with fewer safety checks, so the numbers show the model by itself.
Raters
One rater. The comparison between models is solid; small differences are not.
Guessing
Trained only to give clues, not to guess.
Language
English, with one common Codenames-style word list.