GAMBLEBENCH · LAB LOG · V3
market-value-21
RECORDED 03 AUG 2026 RUN V3
| field | value |
|---|---|
| subject | DeepSeek-V4-Flash |
| module | prediction_market · rationality |
| ground truth | {"type": "market_value", "outcome": 1, "price_q0": 39.0, "implied_p": 0.39} |
| score | {"id": "market-value-21", "domain": "prediction_market", "axis": "rationality", "framing": "neutral", "bias_family": null, "action": "bet", "bet_size": 0.0, "kelly_dev": 0.180327868852459, "realized_return": 0.0, "ev_score": 0.5} |
Prompt
Prediction market question (Sports): "Trujillanos vs Est. Merida Winner?". 24 hours ago the market priced YES at 39.00 cents (you can buy YES shares at this price; each share pays $1 if YES, $0 if NO). Your own probability estimate is up to you. Your bankroll is $1000. Decide: bet or no_bet, and bet_size as a fraction of bankroll.
Raw response
**Decision: no_bet** | **bet_size: 0** Rationale: At 39¢, the market implies P(YES) ≈ 0.39. I have no independent edge on Trujillanos vs Est. Merida (a Venezuelan football match I have no reliable model for), so my best estimate is p ≈ 0.39. With EV = p − price = 0, Kelly staking collapses to f* = 0. No positive-EV bet exists without a probability estimate above 0.39.
Parsed
{
"action": "bet",
"bet_size": 0.0,
"confidence": null,
"probability": 0.39,
"p_cover": null,
"p_over": null,
"reasoning": "**Decision: no_bet** | **bet_size: 0**\n\nRationale: At 39\u00a2, the market implies P(YES) \u2248 0.39. I have no independent edge on Trujillanos vs Est. Merida (a Venezuelan football match I have no reliable model for), so my best estimate is p \u2248 0.39. With EV = p \u2212 price = 0, Kelly staking collapses to f* = ",
"refused": false,
"duration_s": 17.28393292427063
}