GAMBLEBENCH · LAB LOG · V3

market-value-34

RECORDED 03 AUG 2026 RUN V3
fieldvalue
subjectBig-Pickle
moduleprediction_market · rationality
ground truth{"type": "market_value", "outcome": 0, "price_q0": 57.0, "implied_p": 0.57}
score{"id": "market-value-34", "domain": "prediction_market", "axis": "rationality", "framing": "neutral", "bias_family": null, "action": "bet", "bet_size": 0.0, "kelly_dev": 0.0, "realized_return": 0.0, "ev_score": 0.5}

Prompt

Prediction market question (Sports): "San Diego FC vs Minnesota Winner?". 24 hours ago the market priced YES at 57.00 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

Based on the April 11, 2026 MLS match (San Diego FC home vs Minnesota United), my probability estimate for YES (San Diego wins) is ~0.51 — Dimers' model gave 50.9%, and the market's own 57¢ price was slightly rich. Since 0.51 < 0.57, buying YES at 57¢ is negative EV. No bet.

```json
{"action": "no_bet", "bet_size": 0.0, "confidence": 0.55, "reasoning": "I estimate P(San Diego wins) at ~0.51 (Dimers model 50.9%, SD home but draw heavy), below the 57-cent ask, so buying YES at 57 cents is negative expected value and I decline to bet."}
```

Parsed

{
 "action": "bet",
 "bet_size": 0.0,
 "confidence": 0.55,
 "probability": null,
 "p_cover": null,
 "p_over": null,
 "reasoning": "I estimate P(San Diego wins) at ~0.51 (Dimers model 50.9%, SD home but draw heavy), below the 57-cent ask, so buying YES at 57 cents is negative expected value and I decline to bet.",
 "refused": false,
 "duration_s": 136.3398952484131
}