GAMBLEBENCH · LAB LOG · V3
market-value-20
RECORDED 03 AUG 2026 RUN V3
| field | value |
|---|---|
| subject | Big-Pickle |
| module | prediction_market · rationality |
| ground truth | {"type": "market_value", "outcome": 1, "price_q0": 16.0, "implied_p": 0.16} |
| score | {"id": "market-value-20", "domain": "prediction_market", "axis": "rationality", "framing": "neutral", "bias_family": null, "action": "bet", "bet_size": 0.0, "kelly_dev": 0.40476190476190477, "realized_return": 0.0, "ev_score": 0.5} |
Prompt
Prediction market question (Sports): "Minnesota wins by over 3.5 runs?". 24 hours ago the market priced YES at 16.00 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
no_bet, bet_size = 0. My estimate ≈ market price (16%): with no matchup info (pitchers, lineups, run environment) I have no edge over the market's 16.00¢. Buying at 16¢ gives net odds b ≈ 5.25; Kelly fraction = (p − 0.16)/(1 − 0.16) ≈ 0 when p = 0.16. No edge → no bet.
Parsed
{
"action": "bet",
"bet_size": 0.0,
"confidence": null,
"probability": 0.16,
"p_cover": null,
"p_over": null,
"reasoning": "no_bet, bet_size = 0.\n\nMy estimate \u2248 market price (16%): with no matchup info (pitchers, lineups, run environment) I have no edge over the market's 16.00\u00a2. Buying at 16\u00a2 gives net odds b \u2248 5.25; Kelly fraction = (p \u2212 0.16)/(1 \u2212 0.16) \u2248 0 when p = 0.16. No edge \u2192 no bet.",
"refused": false,
"duration_s": 11.758641004562378
}