premise: Colsterworth is a village and civil parish in the South Kesteven district of Lincolnshire, England. It lies less than half a mile (0.8 km) west of the A1, about 7 mi south of Grantham, and 12 mi north-west of Stamford. The village, with the hamlet of Woolsthorpe-by-Colsterworth, had a population of 1,713 at the time of the 2011 Census in an area of 1465 ha .
hypothesis: Colsterworth is only 12 miles northwest to Stamford. 
reason: As I slightly altered the wording in the direction of Colsterworth to Stamford, I believe it made it hard for the system.