BETTING RESEARCH / REFERENCE MARKETS

Top-down betting: start with the market, then check the price.

Top-down betting starts with market prices as a benchmark for evaluating another offer. Instead of building a player projection from scratch, you ask whether a reference market suggests that the available price is favorable. The benchmark can be wrong; this is a research method, not a way to guarantee profit.

Top-down versus bottom-up

A bottom-up approach builds a probability estimate from factors such as player usage, team matchups and projected statistics. A top-down approach begins with reference prices and their implied probabilities. You can use both, but you should know which assumption produces your displayed edge.

1. Match the exact market first

Match the event, player, date, period, side and line. Josh Allen over 40.5 rushing yards and over 45.5 are different selections. So are regulation-only and overtime-inclusive markets. Check participation, push and void rules. Do not compare two prices merely because the player and stat sound similar.

2. Choose a usable benchmark

In PropGoat Odds Edge, Pinnacle is the default de-vig reference. You can inspect other available references, including Novig and BookMaker, but the name of a book alone does not make every market reliable. A thin, stale, incomplete or unusually wide market can be a weak benchmark.

Use a complete opposing pair at the same line, inspect the reference market width, and look for additional context when available. PropGoat’s width filter constrains the paired reference price spread; it is not a measure of how many yards or points separate two lines.

3. Remove the reference margin

At −110 on each side, implied probabilities are approximately 52.38% and 52.38%. Proportional de-vigging divides each by their total, yielding 50% and 50%. An offered +110 at that exact line then has 0.50 × 2.10 − 1 = +5% estimated EV before fees. The estimate still assumes the reference is a useful probability benchmark.

Read the full worked expected-value example or use the free EV calculator with your own assumptions.

4. Inspect independent references or a consensus

Independent mode keeps reference estimates separate, including markets covered by only one selected reference. Weighted Consensus is an alternative: choose contributing books, positive weights, minimum coverage, any required books and how many references must individually meet your EV threshold.

For example, 40/30/30 weights do not require three contributing books unless your coverage settings do. If a reference is absent and your rules permit it, weights are normalized across usable contributors. The target book is excluded. The blended edge and individual agreement checks must both pass. Reference prices are not independent votes, and a consensus can share the same errors.

5. Use filters to make the comparison reviewable

Choose your target books, displayed columns, odds range, minimum EV and width limits. A tight filter can reduce the list; it cannot turn an inaccurate estimate into a good bet. Check why a result qualifies and whether it remains available at the book. The Consensus setup guide covers the actual controls.

6. Verify freshness and the executable offer

PropGoat uses collected snapshots. A new collection timestamp means the data was retrieved again, not that the upstream book necessarily updated its quote at that instant. Check current odds and lines in the actual sportsbook or DFS app. If a line moves or the rules differ, reassess the comparison.

Use supported add-to-slip links as a convenience. They do not reserve odds or submit a bet, and some links open a market without transferring the selection. For parlays, correlation and reduced payouts can invalidate a simple multiplication-based estimate.

Keep the risk visible

A losing result does not prove the calculation was wrong, and a winning result does not validate it. Probability error, fees, changing limits and correlated selections all matter. Keep a record of what you compared and what you actually received, and never treat a research board as guaranteed income.

See how PropGoat’s EV tools support this workflow, or begin with the simpler line-shopping guide. PropGoat is research software, not personal betting or staking advice.