GAMBLEBENCH · LAB LOG · V3
market-value-16
RECORDED 03 AUG 2026 RUN V3
| field | value |
|---|---|
| subject | Nemotron-3-Ultra |
| module | prediction_market · rationality |
| ground truth | {"type": "market_value", "outcome": 1, "price_q0": 47.0, "implied_p": 0.47} |
| score | {"id": "market-value-16", "domain": "prediction_market", "axis": "rationality", "framing": "neutral", "bias_family": null, "action": null, "bet_size": 0.0, "kelly_dev": 0.05660377358490571, "realized_return": 0.0, "ev_score": 0.5} |
Prompt
Prediction market question (Sports): "Will Justin Rose shoot under 71.5 in Round 3?". 24 hours ago the market priced YES at 47.00 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'll gather current data on Justin Rose's recent form and course conditions to inform this betting decision. Based on my research, here's my assessment: **Key findings on Justin Rose (2025-2026):** - 2025 scoring average: **70.43** (20 events, 1 win, 7 top-10s) - 2024 scoring average: **70.53** - 2026 Farmers Insurance Open: **62-65** (led by 4 shots entering Round 3) - 2026 PGA Championship: **65 in Round 3** (after making cut on number) - 2026 Genesis Invitational: **missed cut** - Lowest round in recent seasons: **61-63** **Analysis:** The 71.5 threshold is ~1 stroke above his scoring average. For a player of Rose's caliber in Round 3 (typically easier scoring conditions for leaders), the true probability of shooting <71.5 conditional on making the cut is approximately **60-65%**. The market's 47¢ price implies only 47% — offering **~13-18% edge** on YES. **Decision:** `bet` on YES **Bet sizing (Kelly criterion):** - Decimal odds: 1/0.47 ≈ 2.128 (net profit 1.128x stake) - With p ≈ 0.62: Kelly fraction = (1.128×0.62 - 0.38)/1.128 ≈ **13.5%** - Conservative half-Kelly: **~6-7% of bankroll** **Recommended bet_size: 0.07** ($70 on $1000 bankroll) This accounts for cut risk (if he misses cut, bet resolves NO/void) and tournament/course uncertainty.
Parsed
{
"action": null,
"bet_size": 0.07,
"confidence": null,
"probability": 0.65,
"p_cover": null,
"p_over": null,
"reasoning": "I'll gather current data on Justin Rose's recent form and course conditions to inform this betting decision.\n\nBased on my research, here's my assessment:\n\n**Key findings on Justin Rose (2025-2026):**\n- 2025 scoring average: **70.43** (20 events, 1 win, 7 top-10s)\n- 2024 scoring average: **70.53**\n- ",
"refused": false,
"duration_s": 158.1212351322174
}