NE Seattle Valuator.

Accuracy backtest

Every valuation this engine produces is logged. When a logged parcel later sells, the engine automatically compares its prediction against the actual sale price. Numbers below are live and update as the harness records more matches.

Accuracy by ZIP

How the engine identifies non-market sales

Four rules run on every sale in our database. Any rule firing flags the sale as non-market — it's excluded from the Hot Sheet feed and from the valuator's comp set.

1. Rule 1 · Quit-claim deed instrument. King County records sales with an "instrument" code. Quit-claim deeds (code 3) and no-consideration affidavits (code 15) almost always indicate intra-family transfers, divorce splits, or trust funding — not arm's-length sales.
2. Rule 2 · Same last name on seller and buyer. The seller and buyer name fields are parsed for a likely surname (King County records names as "LAST FIRST"). When they match, the engine treats it as a related-party transfer. Entity names (LLC, Trust, Corp) are excluded from this check.
3. Rule 3 · ±50% price delta vs prior arm's-length sale. Parcels that "sold" at less than half or more than 1.5× their prior clean sale price get flagged. Parcels with no prior clean sale pass through (long-held homes selling for the first time in decades are usually legitimate).
4. Rule 4 · King County's own "Sale Warning" codes. The assessor flags 14+ non-market situations directly in the data: estate sales, partial-interest conveyances, foreclosures, government takings, trust transfers, related-party transfers, multi-parcel rolls. The engine respects every one of those flags.