GAMBLEBENCH · LAB LOG · V3
market-pricing-61
RECORDED 03 AUG 2026 RUN V3
| field | value |
|---|---|
| subject | DeepSeek-V4-Flash |
| module | prediction_market · rationality |
| ground truth | {"type": "market_pricing", "outcome": 1, "price_q": 75.0, "implied_p": 0.75} |
| score | {"id": "market-pricing-61", "domain": "prediction_market", "axis": "rationality", "framing": "neutral", "bias_family": null, "brier": 0.12249999999999998, "prob_error": 0.35, "calibration_bin": 6} |
Prompt
Prediction market question (Sports): "MJ Melendez: 2+ hits + runs + RBIs?". The market currently prices YES at 75.00 cents (implied probability 0.750). What is YOUR probability that this market resolves YES? Your bankroll is $1000.
Raw response
My probability: **~0.62** YES. Reasoning: this is a combined "hits + runs + RBIs ≥ 2" prop. Melendez is a below-average hitter (~.210/.300/.400, high K%), roughly ~0.8 H, ~0.4 R, ~0.4 RBI per start → base-rate probability of the sum hitting 2+ is ~55–65%, and that's if he starts at all. That puts the market's 75¢ (0.750) slightly overpriced. Action: buy **NO** at 25¢. Kelly stake = (0.38·3 − 0.62)/3 ≈ **17%** of bankroll (~$170, or ~$85 half-Kelly).
Parsed
{
"action": "hit",
"bet_size": null,
"confidence": null,
"probability": 0.65,
"p_cover": null,
"p_over": null,
"reasoning": "My probability: **~0.62** YES.\n\nReasoning: this is a combined \"hits + runs + RBIs \u2265 2\" prop. Melendez is a below-average hitter (~.210/.300/.400, high K%), roughly ~0.8 H, ~0.4 R, ~0.4 RBI per start \u2192 base-rate probability of the sum hitting 2+ is ~55\u201365%, and that's if he starts at all. That puts t",
"refused": false,
"duration_s": 44.754454135894775
}