Definition of "every inch"

Wigan looked every inch a side languishing in the relegation zone and there was never any indication they would arrest a run that had seen them lose all of their previous eight Premier League matches at Arsenal.

2011 January 22, Ian Hughes, “Arsenal 3 - 0 Wigan”, in BBC‎

The latter two required a long track walk from Whitechapel (after services ended and power was switched off), alongside TfL staff who know every inch of this historic stretch of line.

2021 June 30, Tim Dunn, “How we made... Secrets of the London Underground”, in RAIL, number 934, page 49