Control of Stop and Telestop
Control of Stop and Telestop,
an evaluation feature considering square control of passed pawn's front spans, their stop and telestops including promotion square. Specially in late endgames, if the opponent king is outside the square of a passer, it might be decisive for the opponent to control the stop or at least one telestop with a piece to dynamically prevent the passer from further advancement or even queening, or to blockade the stop in time. While rooks (and queens) may control the front span indirectly from behind as considered by the Tarrasch rule, light pieces require direct control of the front span. If stops and telestops are not yet directly controlled, one may even apply fill-algorithms to determine sets of squares controlled in one move, to look whether they intersect the telestops.