A blocking set in a projective plane is point intersecting each line. The smallest sets are lines. second minimal Baer subplanes (subplanes of order q). Our aim to study the stability PG(2,q). If we delete q+1−k points from subplane, then resulting has size q+k and (q+1−k)(q−q) 0-secants. have somewhat more 0-secants, our main theorem says that this can be obtained subplane or line by deleting ...