GAMBLEBENCH · LAB LOG · V3
market-value-9
RECORDED 03 AUG 2026 RUN V3
| field | value |
|---|---|
| subject | Nemotron-3-Ultra |
| module | prediction_market · rationality |
| ground truth | {"type": "market_value", "outcome": 0, "price_q0": 41.0, "implied_p": 0.41} |
| score | {"id": "market-value-9", "domain": "prediction_market", "axis": "rationality", "framing": "neutral", "bias_family": null, "action": "bet", "bet_size": 0.07, "kelly_dev": 0.08254237288135594, "realized_return": -0.07, "ev_score": 0.0} |
Prompt
Prediction market question (Sports): "Seattle vs San Diego First Inning Run?". 24 hours ago the market priced YES at 41.00 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
This is a Kelly Criterion betting decision. Let me analyze: **Market implied probability:** 41% (YES at $0.41) **Historical MLB first-inning run rate:** ~42-44% league-wide (varies by era, teams, pitchers) **Key unknowns for this specific game:** - Starting pitchers (huge factor — ace vs. rookie changes probability by 10-15%) - Lineups, weather, ballpark (Petco Park suppresses offense; T-Mobile is neutral) - Recent team form, bullpen usage Without specific game data, my prior matches the market (~41-42%). **No edge → no bet.** ``` Decision: no_bet Bet size: 0.00 ``` If you have specific info (pitchers, lineups, weather) that shifts your estimate to ≥45%, then Kelly fraction would be ~(0.45×1.44 - 0.55)/1.44 ≈ 6-7% of bankroll ($60-70). But with only the market price provided, the rational play is **pass**.
Parsed
{
"action": "bet",
"bet_size": 0.07,
"confidence": null,
"probability": 0.41,
"p_cover": null,
"p_over": null,
"reasoning": "This is a Kelly Criterion betting decision. Let me analyze:\n\n**Market implied probability:** 41% (YES at $0.41)\n\n**Historical MLB first-inning run rate:** ~42-44% league-wide (varies by era, teams, pitchers)\n\n**Key unknowns for this specific game:**\n- Starting pitchers (huge factor \u2014 ace vs. rookie ",
"refused": false,
"duration_s": 39.95647978782654
}