How to find value bets on Polymarket: 5-step framework

A value beton Polymarket is one where your estimated probability of the outcome exceeds the market's implied probability by enough to cover costs. Here's a repeatable process.

Step 1 — Filter by liquidity (≥ $10k)

Low-liquidity markets have wide spreads that eat edge. Ignore markets with less than $10k of book depth. You'll lose 3-5% to slippage even if your call is perfect.

Step 2 — Cross-check sharp books

Look at Pinnacle, Betfair Exchange, Kalshi, and decentralised prediction books. If all sharp books agree at 55-57% and Polymarket shows 65¢, something is off. Likely Polymarket is the outlier (either a trade imbalance or information lag). That's a sign of value.

Step 3 — Build a probability estimate

For sports: combine historical base rates, recent form, and injury/availability news. For political markets: weight recent polls by reliability + apply an FTM (fundamentals model). For crypto: consider base rates for threshold events (e.g. “ETH above $X” — historical volatility informs).

Rule: if you're not confident enough to estimate within ±10pp, skip.

Step 4 — Measure edge and apply thresholds

• Edge = your probability − market price (in percentage points)
• Minimum edge for action: 5pp after costs.
• Minimum confidence: you should be comfortable with the probability estimate to ±5pp.

Step 5 — Size with fractional Kelly

Kelly fraction for a binary bet: f = (bp - q) / b where b = (1 - price)/price, p = your probability, q = 1 - p.

In practice, use ½ or ¼ Kelly to dampen variance. Never more than 2% of bankroll on a single bet. Even a correct bet can lose — the goal is to bet proportionally often enough that the math works.

Where PolyGuru fits

We run all five steps automatically on 1,500+ Polymarket markets daily. The output is a short-list of markets that pass every filter — you still decide whether to act, but you save the 3 hours of research per pick.