GAMBLEBENCH · LAB LOG · V3
market-pricing-15
RECORDED 03 AUG 2026 RUN V3
| field | value |
|---|---|
| subject | DeepSeek-V4-Flash |
| module | prediction_market · rationality |
| ground truth | {"type": "market_pricing", "outcome": 0, "price_q": 5.0, "implied_p": 0.05} |
| score | {"id": "market-pricing-15", "domain": "prediction_market", "axis": "rationality", "framing": "neutral", "bias_family": null, "brier": 0.002025, "prob_error": 0.045, "calibration_bin": 0} |
Prompt
Prediction market question (Sports): "Nico Hoerner: 1+ home runs?". The market currently prices YES at 5.00 cents (implied probability 0.050). What is YOUR probability that this market resolves YES? Your bankroll is $1000.
Raw response
**My probability: ~4.5%** (slightly below the market's 5.0%). Reasoning: Nico Hoerner is a low-power contact hitter. His recent full seasons: ~7 HR in 155 games (2024), ~9 in 150 (2023) → roughly 4.5–6% per game of hitting exactly one. Slight downward adjustment for a low-ISO profile (~.09) and typical park effects puts me at ~4.5%. The market at 5% is essentially efficient here — no big edge. **Position:** SELL YES (buy NO at ~95¢). My edge is thin. - EV/share: ~0.045 → buy NO: 0.955 × 1 − 0.95 = +0.005 (≈0.5% ROI on capital) - Full Kelly ≈ 10% of bankroll; at half-Kelly, stake ~**$50** on NO. Expected value: +~$0.27 per NO share, so a modest $50 bet is reasonable and low-variance, but the edge is small enough that passing is defensible too.
Parsed
{
"action": "no_bet",
"bet_size": 0.1,
"confidence": null,
"probability": 0.045,
"p_cover": null,
"p_over": null,
"reasoning": "**My probability: ~4.5%** (slightly below the market's 5.0%).\n\nReasoning: Nico Hoerner is a low-power contact hitter. His recent full seasons: ~7 HR in 155 games (2024), ~9 in 150 (2023) \u2192 roughly 4.5\u20136% per game of hitting exactly one. Slight downward adjustment for a low-ISO profile (~.09) and typ",
"refused": false,
"duration_s": 25.21612787246704
}