Methodology

Scope, cadence, and sources

Primary inventory coverage is Maricopa County, Arizona, with limited records from other researched counties. Discovery uses recorder, sheriff, trustee, and auction-source captures; parcel context may use county assessor data. Each issue shows the retrieval date actually present in the source snapshot.

Evidence labels on every input

• verified — read from the named source, with a retrieval timestamp. Current auction status still requires an allowlisted official status source.
• estimated — an analyst or model estimate; the source of the estimate is named.
• unknown — we do not know. Unknown required inputs make dependent metrics read “unknown”. They are never silently treated as zero.
• excluded — affirmatively verified as not applicable (e.g. “no buyer premium at AZ trustee sales”). Contributes zero with an audit trail — which is different from unknown.

Opening-bid observations

The bid registry keeps opening bids, current bids, creditor bids, and minimum bids as separate observation types. It matches records by exact normalized APN first and uses a state-aware street-address fallback only when the observation has no parcel identifier. A numeric bid populates the live field only when its source URL and retrieval time are present, the observation is no more than 72 hours old, its sale date is not past, and its status is not sold, cancelled, closed, completed, or postponed. Older observations remain historical evidence and never silently become a current opening bid. A bid observation does not confirm that the auction itself remains active.

Freshness states and the gate

A record appears under “verified upcoming auctions” only when a retrieval from the official source is younger than 72 hours, confirms status “upcoming”, and carries a future sale date. Everything else is bucketed as a watchlist signal (resolved identity, unverified auction, signal younger than 14 days), stale, unresolved, historical, or a labeled example. A notice of default is a distress signal, never an auction. A notice of trustee sale proves only what was scheduled when recorded. It is not a current-status confirmation because Arizona permits oral postponement. Only a fresh trustee/current-status source can pass the upcoming-auction gate.

The cost model

proceeds(exit)  = exit × (1 − sellingCost%)
bidCosts(bid)   = bid × (1 + buyerPremium%)
                + leverage × bid × (points% + rate% × months / 12)
fixedCosts      = repair + contingency(15% of repair)
                + monthlyCarry × months
                + closing/recording + title/escrow
                + delinquentTaxes + HOA/municipal exposure
monthlyCarry    = insurance + utilities + taxes + HOA (monthly)
netProfit       = proceeds − bidCosts − fixedCosts
cashRequired    = totalProjectCost − (leverage × bid)
cashOnCash      = netProfit / cashRequired
annualized      = cashOnCash × 12 / holdMonths
breakEven price = allCosts / (1 − sellingCost%)

Maximum bids — conservative by default

Each maximum bid solves netProfit = requiredProfit for the bid:

• Conservative (the default ceiling): LOW exit value, HIGH repair, HIGH hold months; required profit = max($25,000, 10% of exit).
• Target: BASE value, BASE repair, BASE hold; 80% of the conservative profit requirement.
• Aggressive: BASE value, LOW repair, 50% of the requirement. Shown to expose how thin the margin gets — it is not a recommendation.

What is verified, estimated, unknown, or excluded

Today, concretely:

• Verified where shown: recorder instrument numbers, document types, recording dates, resolved property addresses, parcel facts, source-linked bid observations, and retrieval timestamps. Owner names are excluded from public issue copy.
• Estimated: valuation ranges, repair ranges, financing terms, cost-stack items on the labeled example.
• Unknown: unmatched or expired opening bids, sale dates, occupancy, liens, and taxes not carried by the source record. Unknown required inputs remain unknown and prevent dependent calculations.
• Excluded from the model entirely: eviction/possession costs, HOA super-lien nuances, and IRS-redemption carrying costs are not yet modeled anywhere; they appear only as risk flags. If a flag applies, the real number is worse than the model.

Failure states — how the model refuses

• A missing required input nulls every dependent metric and lists what is missing.
• Missing title, lien, occupancy, tax, repair, or auction-rule evidence lowers status to “requires human review” and raises visible risk flags.
• A record with missing required values can be shown as a watchlist signal, but the system will not label it “underwritten”, “investment-ready”, “verified opportunity”, or “buy”.
• A stale record cannot enter the upcoming-auctions list at all, regardless of what its old data says.