GAMBLEBENCH · LAB LOG · V3
market-value-6
RECORDED 03 AUG 2026 RUN V3
| field | value |
|---|---|
| subject | Big-Pickle |
| module | prediction_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, "refused": true, "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
**Decision: no_bet, bet_size = 0** My probability estimate for YES (NY Y wins by 3+ runs): **~0.30** Reasoning: - Baseball win margins concentrate at 1–2 runs; only ~50% of wins are by 3+ runs. - Backing out of the 0.34 price, that implies NY Y wins the game ~0.34/0.50 ≈ 68% of the time — a very heavy favorite I can't confirm without the moneyline. - For a more typical favorite (~60–64% win prob), fair YES ≈ 0.30–0.32. Buying YES at $0.34 is negative EV (EV ≈ -$0.04/share), and Kelly on a negative-EV bet is 0. No bet.
Parsed
{
"action": "bet",
"bet_size": 0.0,
"confidence": null,
"probability": 0.5,
"p_cover": null,
"p_over": null,
"reasoning": "**Decision: no_bet, bet_size = 0**\n\nMy probability estimate for YES (NY Y wins by 3+ runs): **~0.30**\n\nReasoning:\n- Baseball win margins concentrate at 1\u20132 runs; only ~50% of wins are by 3+ runs.\n- Backing out of the 0.34 price, that implies NY Y wins the game ~0.34/0.50 \u2248 68% of the time \u2014 a very h",
"refused": true,
"duration_s": 26.671998023986816
}