How do Fallbacks Work?

{
	"warning": "Default search radius (1.5 miles, 180 days back) returned insufficient comps. Automatically expanded to 10 miles and 180 days back.",
  "fallback": {
    "applied": true,
    "reason": "insufficient_comps_on_defaults",
    "message": "Initial search with default 1.5 mile radius and 180 days back returned 0 comps (below threshold of 3). Automatically expanded to 10 miles and 180 days back.",
    "thresholdMinComps": 3,
    "initialAttempt": {
      "max_radius_miles": 1.5,
      "max_days_back": 180,
      "compsFound": 0
    },
    "expandedAttempt": {
      "max_radius_miles": 10,
      "max_days_back": 180,
      "compsFound": 26
    }
  }
}