Changes

formulated by [https://en.wikipedia.org/wiki/Siegbert_Tarrasch Siegbert Tarrasch], is a [https://en.wikipedia.org/wiki/Rule_of_thumb rule of thumb] (heuristic) applied in [[Endgame|endgames]] and sometimes (late) [[Middlegame|middlegames]] with [[Passed Pawn|passed pawn(s)]] and [[Rook|rook(s)]] involved. Rooks should be placed "behind" own passers as well as [[Candidate Passed Pawn|candidates]] to support them, as well "behind" opponent passers to hold them.

The advantage of a rook intersecting the passers [[Pawn Spans|rear span]] is that it does not hinder the passer from [[Promotions|queening]], but indirectly controls its [[Stop Square|stop square]] with increasing vertical rook [[Mobility|mobility]] the more the passer advances. Since the passers rear spans might also be occupied by other pieces, specially own or opponent file-immobile pawns, the passer should actually be defended or attacked by a rook from south (white passer) or north (black passer). Alternatively, with [[Bitboards|bitboards]] and [[Fill Algorithms|fill stuff]] in mind, to determine the relevant subset of the rear span, the north- or south [[Dumb7Fill#OccludedFill|Dumb7-]] or [[Kogge-Stone Algorithm#OccludedFill|Kogge-Stone occluded fill]] might be applied, only with pawns of both sides as obstructions.

=See also=