P to KR3 to restrain the adverse Queens Bishop from pinning your Knight at KB3 is deprecated by the modern school. For although it does not always compromise the game yet it mostly loses time and give unnecessary trouble on the Kings side. When attacking a hostile piece the advance of the Books Pawn becomes useful in order to make room for the knight, as well as for dislodging an opponent's piece-- (steinitz) Free Chess Moves Video Course Here.

Advanced Pawn should be supported from the side of the board and not from the center. A queen Pawn used as a supporting Pawn is especially weak, being open to attack on all sides. Free Chess Moves Video Course Here

On the same principle, a supporting piece should always be placed where be is least liable to attack, or where, if attacked, be can support while retreating. For this reason a Knight is inferior as a supporting piece. A good player will aim at the support rather than at the front rank.

A rook on the same fiile as your opponent's king or queen is always well placed, intervening men notwithstanding. In the former position, with queen and the other Rook on adjoinging files, you may generally force the game. This is easier if the intervening Pawn are disarranged. This principle me be extended to the queen and two Bishop on three adjoining diagonal bearing upon the adverse King's quarters, but the rule is not so certain in the case unless there are advanced pawns to assist in the attack. Free Chess Moves Video Course Here

In exchanging aim at securing a majority of pawns on your Qwueen's side. That is if your King is castled on the other side.