GAMBLEBENCH · LAB LOG · V3
market-value-23
RECORDED 03 AUG 2026 RUN V3
| field | value |
|---|---|
| subject | Big-Pickle |
| module | prediction_market · rationality |
| ground truth | {"type": "market_value", "outcome": 0, "price_q0": 47.0, "implied_p": 0.47} |
| score | {"id": "market-value-23", "domain": "prediction_market", "axis": "rationality", "framing": "neutral", "bias_family": null, "action": "bet", "bet_size": 0.0, "kelly_dev": 0.05660377358490571, "realized_return": 0.0, "ev_score": 0.5} |
Prompt
Prediction market question (Sports): "Will Nate Landwehr win the Swanson vs Landwehr professional MMA fight scheduled for Apr 11, 2026?". 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
**Decision: no_bet, bet_size = 0** Rationale: I have no information advantage over the market here. My honest probability estimate for Landwehr winning is ~47%, essentially the market price of 47¢. Kelly criterion for a zero-edge bet is 0% of bankroll — betting would just add variance with no positive expected value (and negative EV after any fees/slippage). If I had a genuine, non-public edge that pushed my estimate to, say, 60%+, Kelly would suggest ~ (0.60×1 − 0.53)/1 ≈ 7% of bankroll (fractional Kelly less). But without an edge, the correct action is to sit out.
Parsed
{
"action": "bet",
"bet_size": 0.0,
"confidence": null,
"probability": 0.47,
"p_cover": null,
"p_over": null,
"reasoning": "**Decision: no_bet, bet_size = 0**\n\nRationale: I have no information advantage over the market here. My honest probability estimate for Landwehr winning is ~47%, essentially the market price of 47\u00a2. Kelly criterion for a zero-edge bet is 0% of bankroll \u2014 betting would just add variance with no posit",
"refused": false,
"duration_s": 12.931857109069824
}