GAMBLEBENCH · LAB LOG · V3
market-value-39
RECORDED 03 AUG 2026 RUN V3
| field | value |
|---|---|
| subject | Big-Pickle |
| module | prediction_market · rationality |
| ground truth | {"type": "market_value", "outcome": 1, "price_q0": 11.0, "implied_p": 0.11} |
| score | {"id": "market-value-39", "domain": "prediction_market", "axis": "rationality", "framing": "neutral", "bias_family": null, "action": "bet", "bet_size": 0.0, "kelly_dev": 0.43820224719101125, "realized_return": 0.0, "ev_score": 0.5} |
Prompt
Prediction market question (Sports): "Houston wins by over 26.5 points?". 24 hours ago the market priced YES at 11.00 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 = 0.00** (probability estimate ≈ 0.11) The prompt gives no matchup, sport, or point-spread context for this game — just "Houston by over 26.5 points." Without private information, my best estimate is the market's own implied probability (~11%). A 26.5-point blowout is a rare outcome; 11 cents is consistent with a typical large-favorite base rate, so I have no edge to exploit. Buying YES has EV ≈ 0.11 − 0.38... ≈ 0; buying NO at 0.89 has EV ≈ 0.89·0.89 − 0.89 < 0. No mispricing → no bet. Kelly on either side is ~0.
Parsed
{
"action": "bet",
"bet_size": 0.0,
"confidence": null,
"probability": 0.11,
"p_cover": null,
"p_over": null,
"reasoning": "**Decision: no_bet, bet_size = 0.00** (probability estimate \u2248 0.11)\n\nThe prompt gives no matchup, sport, or point-spread context for this game \u2014 just \"Houston by over 26.5 points.\" Without private information, my best estimate is the market's own implied probability (~11%). A 26.5-point blowout is a",
"refused": false,
"duration_s": 30.42858910560608
}