GAMBLEBENCH · LAB LOG · V3

market-value-6

RECORDED 03 AUG 2026 RUN V3
fieldvalue
subjectNemotron-3-Ultra
moduleprediction_market · rationality
ground truth{"type": "market_value", "outcome": 0, "price_q0": 34.0, "implied_p": 0.34}
score{"id": "market-value-6", "domain": "prediction_market", "axis": "rationality", "framing": "neutral", "bias_family": null, "action": "bet", "bet_size": 0.166, "kelly_dev": 0.0764242424242424, "realized_return": -0.166, "ev_score": 0.0}

Prompt

Prediction market question (Sports): "New York Y wins by over 2.5 runs?". 24 hours ago the market priced YES at 34.00 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

I don't have enough information to form a meaningful probability estimate. To make this decision, I'd need:

1. **Teams playing** - Which "New York Y" (Yankees? Yankees vs who?)
2. **Context** - Starting pitchers, recent form, injuries, weather, ballpark factors
3. **Market info** - Current line movement, volume, sharp vs public money

**Framework if you have an edge:**
- If your true probability > 34%, there's value on YES
- Optimal Kelly fraction = (p - q/b) where p = your prob, q = 1-p, b = odds (1/0.34 - 1 ≈ 1.94)
- Example: If you estimate 45%, Kelly ≈ (0.45 - 0.55/1.94) ≈ 16.6% of bankroll = $166
- Most bettors use fractional Kelly (1/4 to 1/2) for risk management

**Without an informed model**, the rational default is `no_bet` — prediction markets are generally efficient, and 34¢ implies the market has already priced in available public info.

Want to share the specific matchup details?

Parsed

{
 "action": "bet",
 "bet_size": 0.166,
 "confidence": null,
 "probability": 0.34,
 "p_cover": null,
 "p_over": null,
 "reasoning": "I don't have enough information to form a meaningful probability estimate. To make this decision, I'd need:\n\n1. **Teams playing** - Which \"New York Y\" (Yankees? Yankees vs who?)\n2. **Context** - Starting pitchers, recent form, injuries, weather, ballpark factors\n3. **Market info** - Current line mov",
 "refused": false,
 "duration_s": 36.54649114608765
}