GAMBLEBENCH · LAB LOG · V3
market-value-12
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": 43.0, "implied_p": 0.43} |
| score | {"id": "market-value-12", "domain": "prediction_market", "axis": "rationality", "framing": "neutral", "bias_family": null, "action": "bet", "bet_size": 0.0, "kelly_dev": 0.12280701754385964, "realized_return": 0.0, "ev_score": 0.5} |
Prompt
Prediction market question (Sports): "New York Y wins by over 1.5 runs?". 24 hours ago the market priced YES at 43.00 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 The market at 43 cents is already an efficient aggregation of information, and I have no edge over it on this specific prop. Betting without an edge yields negative expected value, and Kelly sizing says stake 0 when my estimate ≈ market price.
Parsed
{
"action": "bet",
"bet_size": 0.0,
"confidence": null,
"probability": null,
"p_cover": null,
"p_over": null,
"reasoning": "no_bet, bet_size: 0\n\nThe market at 43 cents is already an efficient aggregation of information, and I have no edge over it on this specific prop. Betting without an edge yields negative expected value, and Kelly sizing says stake 0 when my estimate \u2248 market price.",
"refused": false,
"duration_s": 10.071470022201538
}