GPT-4.1 Behavioral Fingerprint
How OpenAI's GPT-4.1 answers one-word probe questions at temperature 1.0 — random numbers, colors, animals, coin flips — measured over 420 valid samples in the open dataset of "One Token Is Enough" (arXiv:2607.10252).
Vendor
OpenAI
Data generated
2026-07-08
Probe cells
14
Valid samples
420
Randomness score
25 / 100
Mean normalized entropy across cells, 0–100. 100 would be a uniform-random baseline; real models score far lower.
Signature answers
Favorite random number (1–100)
47
22 / 30 answers
Favorite color
cerulean
11 / 30 answers
Coin flip: heads
100%
Share of heads across coin-flip cells.
Answer distributions by probe cell
Empirical distributions of normalized one-word answers, per task and language. H is the Shannon entropy in bits; the uniform baseline is log2 of the answer-domain size.
Coin flip · English
n = 30 · H = 0.00 bit · uniform baseline 1.00 bit
| Answer | Count | Share |
|---|---|---|
| heads | 30 | 100.0% |
Coin flip · Chinese
n = 30 · H = 0.00 bit · uniform baseline 1.00 bit
| Answer | Count | Share |
|---|---|---|
| heads | 30 | 100.0% |
Favorite number · Chinese
n = 30 · H = 0.21 bit · uniform baseline 13.29 bit
| Answer | Count | Share |
|---|---|---|
| 7 | 29 | 96.7% |
| 8 | 1 | 3.3% |
Random animal · English
n = 30 · H = 1.96 bit · uniform baseline 5.64 bit
| Answer | Count | Share |
|---|---|---|
| giraffe | 16 | 53.3% |
| elephant | 7 | 23.3% |
| okapi | 3 | 10.0% |
| otter | 1 | 3.3% |
| capybara | 1 | 3.3% |
| ocelot | 1 | 3.3% |
| jaguar | 1 | 3.3% |
Random animal · Chinese
n = 30 · H = 3.63 bit · uniform baseline 5.64 bit
| Answer | Count | Share |
|---|---|---|
| 大象 | 5 | 16.7% |
| 象 | 4 | 13.3% |
| 长颈鹿 | 4 | 13.3% |
| 猩猩 | 3 | 10.0% |
| 熊猫 | 2 | 6.7% |
| 虎 | 2 | 6.7% |
| 考拉 | 2 | 6.7% |
| 刺猬 | 1 | 3.3% |
+ 7 more answers
Random city · English
n = 30 · H = 2.32 bit · uniform baseline 5.64 bit
| Answer | Count | Share |
|---|---|---|
| oslo | 10 | 33.3% |
| kyoto | 8 | 26.7% |
| lisbon | 6 | 20.0% |
| prague | 3 | 10.0% |
| toronto | 1 | 3.3% |
| lyon | 1 | 3.3% |
| toledo | 1 | 3.3% |
Random city · Chinese
n = 30 · H = 3.25 bit · uniform baseline 5.64 bit
| Answer | Count | Share |
|---|---|---|
| 成都 | 8 | 26.7% |
| 巴黎 | 7 | 23.3% |
| 巴塞罗那 | 2 | 6.7% |
| 南京 | 2 | 6.7% |
| 杭州 | 2 | 6.7% |
| 上海 | 1 | 3.3% |
| 福州 | 1 | 3.3% |
| 深圳 | 1 | 3.3% |
+ 6 more answers
Random color · English
n = 30 · H = 2.35 bit · uniform baseline 4.91 bit
| Answer | Count | Share |
|---|---|---|
| cerulean | 11 | 36.7% |
| teal | 8 | 26.7% |
| turquoise | 4 | 13.3% |
| azure | 3 | 10.0% |
| magenta | 2 | 6.7% |
| emerald | 1 | 3.3% |
| cyan | 1 | 3.3% |
Random color · Chinese
n = 30 · H = 0.90 bit · uniform baseline 4.91 bit
| Answer | Count | Share |
|---|---|---|
| 蓝 | 25 | 83.3% |
| 橙 | 2 | 6.7% |
| 紫 | 2 | 6.7% |
| 青 | 1 | 3.3% |
Random letter · English
n = 30 · H = 2.37 bit · uniform baseline 4.70 bit
| Answer | Count | Share |
|---|---|---|
| j | 12 | 40.0% |
| q | 6 | 20.0% |
| k | 5 | 16.7% |
| g | 2 | 6.7% |
| m | 2 | 6.7% |
| h | 2 | 6.7% |
| r | 1 | 3.3% |
Random number 1-10 · English
n = 30 · H = 0.00 bit · uniform baseline 3.32 bit
| Answer | Count | Share |
|---|---|---|
| 7 | 30 | 100.0% |
Random number 1-10 · Chinese
n = 30 · H = 0.00 bit · uniform baseline 3.32 bit
| Answer | Count | Share |
|---|---|---|
| 7 | 30 | 100.0% |
Random number 1-100 · English
n = 30 · H = 0.84 bit · uniform baseline 6.64 bit
| Answer | Count | Share |
|---|---|---|
| 47 | 22 | 73.3% |
| 57 | 8 | 26.7% |
Random number 1-100 · Chinese
n = 30 · H = 1.48 bit · uniform baseline 6.64 bit
| Answer | Count | Share |
|---|---|---|
| 57 | 17 | 56.7% |
| 47 | 9 | 30.0% |
| 37 | 3 | 10.0% |
| 73 | 1 | 3.3% |
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Distributions: Tomáš Bruckner, "One Token Is Enough" (arXiv:2607.10252), official dataset Zenodo DOI 10.5281/zenodo.21278557, licensed CC-BY-4.0. Collected via OpenRouter at temperature 1.0 under the paper's fixed minimal one-word system prompt; answer keys are re-normalized with the checker's pipeline (color aliases, number words, coin h/t) so live probes are directly comparable.