| notyetagm: This game is a showcase for the tactical theme of <RELOADING>, that N defenders cannot keep out N+1 attackers. Consider the position after 19 ...  bd5:
click for larger viewWhite threatens the royal fork 20 e5-g6+. This threat is met only by the Black f7-pawn <DEFENDING> this g6-forking square. But in addition to the White e5-knight, the White g3-rook and b1-bishop also threaten to occupy the g6-square. So White has -three- pieces that threaten to occupy the g6-square (e5-knight, b1-bishop, g3-rook) versus only -one- Black defender (f7-pawn) keeping them out of this square. Since the Black f7-pawn must keep the White e5-knight out of g6, it cannot keep out either the White b1-bishop or g3-rook. So White plays 20  g6!, with the idea that if this bishop is taken by 20 ... fxg6, then White will <RELOAD> on the g6-square with 21 xg6+, winning   for . After 20 g6! e8, the following position is reached: 
click for larger viewThe White d2-queen and c1-bishop both threaten to move to the h6-f8 diagonal by occupying the h6-square in turn. The only Black piece keeping these two White pieces out of h6 is the g7-pawn. But -one- Black defender (g7-pawn) cannot keep out -two- White attackers (d2-queen, c1-bishop). With 21 xh6! White uses yet another <RELOADER>. White's idea is that if Black captures his queen with 21 ... gxh6, then he will <RELOAD> on the h6-square with 22 xh6+, winning. 
click for larger viewOn the g6-square, -one- defender cannot keep out -three- attackers. On the h6-square, -one- defender cannot keep out -two- attackers. These two <RELOADER> examples exploit the one weakness of a pawn defender: even though a pawn is the best defender of a square since it has the lowest value, <a pawn defends a square -only- one time>. The Black f7-pawn defends the g6-square only one time. The Black g7-pawn defends the h6-square only one time. | 
