notyetagm: <IMPORTANT> <IF YOU LINE UP YOUR PIECES, THEN THE REASON WHY SIMPLY DOES NOT MATTER> <IMPORTANT>

Attack an enemy piece - UNDEFENDED White Rd7? to attack Black d5-knight in Alekhine-Lasker St. Petersburg 1914 creates the <DISCOVERY CHAIN White d7-rook + Black d5-knight> which can give check

Block an attack from an enemy line piece - you just lined up your blocking piece with whatever target the enemy line piece attacked

Capture an enemy unit, especially with the support of the queen - Rb3xNb4 in Nimzowitsch-Tartakower Karlsbad 1923 lines up the White b4-rook with the UNDEFENDED White d2-queen, forming the <PINNING CHAIN b4-rook + d2-queen> which Tartakower exploited by ... Qc7-a5!, <PINNING> the White rook to the UNDEFENDED queen

Defend a piece with a line piece - Leko vs Kramnik Amber 2007, White f3-rook defends the loose White f5-bishop, Kramnik exploited this <f5-bishop + f3-rook PINNING CHAIN> with ... Rf2!, winning instantly.

Forming a battery such as doubling on a file or diagonal - variation of Tarrasch vs Vogel Numremburg 1910 in which Black nearly forms the <PINNING CHAIN Black d8-rook + Black d7-rook + White d1-rook> by doubling on the d-file with ... Rf8-d8?, which would have lost to the <DISCOVERED PIN> Nd6xf7+!, exploiting the <PARTIAL PIN> of the Black d7-rook to the Black d8-rook by the White d1-rook

Of these case, seeking to <DEFEND> something with a line piece and <FORMING A BATTERY> are very common reasons why players make the tactical error of lining up their pieces.

Again, if you line up your pieces, it simply does not matter -why- you lined them up. Your opponent will just say <"Thanks for lining up your pieces for me so that I can PIN/SKEWER/FORK them">.

/IMPORTANT <IF YOU LINE UP YOUR PIECES THEN THE REASON WHY SIMPLY DOES NOT MATTER> <IMPORTANT/>