Ruy Lopez 5.d4 exd4 6.Qxd4 and White is in . After 4...dxc6, the obvious 5.Nxe5 is weak, since 5...Qd4 6.Nf3 Qxe4+ 7.Qe2 Qxe2+ leaves White with no compensation for Black's bishop pair. There are two principal lines after 4.Bxc6 dxc6. In the late 19th and early 20th centuries, Lasker had great success with 5.d4 exd4 6.Qxd4 Qxd4 7.Nxd4. Since then, better defences for Black have been developed, and this line is considered to slightly favour Black. Jon Jacobs wrote in the July 2005 "Chess Life" (p. 21): "A database search (limited to games longer than 20 moves, both players FIDE 2300+) reveals
Tactical decision game Tactical decision game A tactical decision game is a decision game that puts students in the role of the commander of a tactical unit who is faced with a challenging problem. While most tactical decision games depict problems faced by the commanders of military units, a growing number deal with the situations of types dealt with by police and firefighting organizations . The tactical decision game is known by a variety of names. These include "map problem", "tactical problem", "one-step war game", and "tactical decision exercise". Like other types of decision games, tactical decision games may either be historical or