How MowSignal checks fit

Fits your yard means all applicable hard constraints pass; Not confirmed by manufacturer means a required fact is missing or unclear; Ruled out means at least one rule fails.

Ruleset version: mowers-2026.10.1. The selector and these examples use the same deterministic rules.

Hard rules

We compare your yard inputs with verified manufacturer specifications. Missing or ambiguous facts cannot confirm a fit; editorial judgments are labelled “Our rule”.

• Lawn area Manufacturer spec

  Your lawn exceeds the published maximum mowing area.

• Slope Manufacturer spec

  Your slope exceeds the published maximum slope.

• Manufacturer price Manufacturer spec

  The verified list price (MSRP) exceeds your budget. If the official store’s own price, observed within the last 7 days, is within your budget, the result is “Not confirmed” instead of “Ruled out”; it never counts as a fit.

• Boundary wire Manufacturer spec

  You require wire-free setup and the mower needs a boundary wire.

• RTK base station Manufacturer spec

  You want to avoid an antenna and the mower requires one.

• Multiple zones Manufacturer spec

  The mower does not support your separate zones or your zone count exceeds its published limit.

• Minimum passage width Manufacturer spec

  Your passage is narrower than the published minimum passage width.

• Passage body-width fallback Our rule

  No minimum passage width is verified, and the mower’s body is wider than your passage.

  Rationale

  A passage narrower than the mower body physically cannot fit it. Body clearance alone does not establish navigation clearance.

• Obstacle climb height Manufacturer spec

  Your bumps exceed the published obstacle climb height.

• Heavy canopy Our rule

  Under heavy tree cover, positioning uses satellites alone with a verified absence of camera positioning.

  Rationale

  Satellite RTK needs open sky. Explicit lidar, vision positioning or boundary-wire navigation provides an alternative; this is an editorial fit rule, not a manufacturer canopy guarantee.

Ranked trade-offs

Editorial scoring

These weights express editorial preferences among products whose manufacturer facts satisfy the yard constraints. Unknown criteria are omitted and known weights are normalized.

Scores range from 0 to 100. Each criterion is clamped to the interval from zero to one. A zero weight makes a criterion inapplicable. Unknown criteria are omitted; known, applicable weights are normalized to sum to one. The score is the weighted sum multiplied by 100; if no criteria are known, the score is zero.

Unknowns and ordering

Unknown does not mean pass. Missing or ambiguous values cannot satisfy an applicable hard constraint. A quoted marketing claim alone cannot establish a numeric limit or a positioning capability.

The gate-width reference applies the same minimum-passage and body-width fallback rules to a 36-inch gate.

Compatible models are ranked by score, then fewer unknowns, then product identifier. Not-confirmed models are ordered by fewer unknown hard constraints, then score, then identifier. Disqualified models are listed by identifier with their failed rules.

Data contract

Each record describes one US variant. Verified facts include canonical units, source URL and type, retrieval date, and a source quote. Text-only claims retain their wording. Missing, ambiguous and not-applicable facts remain distinct.

Conversions use only explicitly stated units. Conflicting official sources remain ambiguous. Manufacturer suggested retail prices are volatile and appear only with their recorded retrieval date. Other monetary amounts in source excerpts are marked [price omitted].

Budget checks and ranking always use the audited list price. Separately, a file of official-store prices is refreshed daily for models whose store publishes its current price in a machine-readable product feed (Shopify store JSON). Prices from eufy, Ecovacs and Husqvarna are not observed: those models use list price only. Your browser uses a store price only if it was observed within the last 7 days and was taken against the same list price we have verified; otherwise it is ignored and results use list price alone. Store prices appear only with their check date, in your browser, and are not savings claims. They do not change scores or a model’s rank within a group.

Scenario publication

Candidates are evaluated in the order steep slopes, heavy tree cover, one-acre lawns, multiple zones and budget limit. A page needs at least three compatible models and a Jaccard distance of at least 0.3 from every previously accepted scenario. Jaccard distance is one minus the number of shared compatible model identifiers divided by the number of distinct identifiers across both sets. At most five scenario pages are published.

Worked examples

• Steep slopes
• Heavy tree cover
• One-acre lawns
• Multiple zones
• Lawns with a budget limit

Source monitoring

The source monitor flags changed quotes or prices, missing critical text and fetch failures for human review. It never approves changes or rewrites facts. Dataset validation runs before every site build.

Model specificationsMerchant link disclosure