GAMBLEBENCH · LAB LOG · V3
market-value-33
RECORDED 03 AUG 2026 RUN V3
| field | value |
|---|---|
| subject | Big-Pickle |
| module | prediction_market · rationality |
| ground truth | {"type": "market_value", "outcome": 0, "price_q0": 22.0, "implied_p": 0.22} |
| score | {"id": "market-value-33", "domain": "prediction_market", "axis": "rationality", "framing": "neutral", "bias_family": null, "action": "bet", "bet_size": 0.0, "kelly_dev": 0.358974358974359, "realized_return": 0.0, "ev_score": 0.5} |
Prompt
Prediction market question (Sports): "Philadelphia wins by over 2.5 runs?". 24 hours ago the market priced YES at 22.00 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 `0.0`** Reasoning: The market price (22¢) implies ~22% for YES. My best probability estimate for a team winning by 3+ runs is close to that consensus, giving no meaningful edge. With zero expected edge, Kelly says bet nothing — any positive stake is just paying the spread. (If I had a superior, well-calibrated estimate of ~30%, the Kelly fraction would be (0.30−0.22)/0.78 ≈ 10%, but I have no basis to override the market here.)
Parsed
{
"action": "bet",
"bet_size": 0.0,
"confidence": null,
"probability": 0.22,
"p_cover": null,
"p_over": null,
"reasoning": "**Decision: `no_bet`, bet_size `0.0`**\n\nReasoning: The market price (22\u00a2) implies ~22% for YES. My best probability estimate for a team winning by 3+ runs is close to that consensus, giving no meaningful edge. With zero expected edge, Kelly says bet nothing \u2014 any positive stake is just paying the sp",
"refused": false,
"duration_s": 23.60975193977356
}