These principles are from IM Cyrus Lakdawala's books and are shared with his permission. His books are available for purchase at the club as well as at Everyman Chess. Strong players routinely use these principles to guide their analysis and assessments, so an understanding of this list is essential to the developing club player.
If ahead in development then open up the position (trade central pawns) or create confrontation; if behind in development then freeze the central pawn structure and avoid confrontation.
If you lag in development and your opponent cannot effectively open the game, then don't worry too much about the lag.
Let your opponent break the central pawn tension unless you have something concrete to gain from it.
In an open game develop rapidly; don’t move the same piece twice.
In a closed game, quality instead of quantity development; pay close attention to the pawn structure.
Outside passed pawns favor inside passed pawns.
Rooks should be placed on open files and should not defend laterally.
In the endgame they should be stationed behind passed pawns (yours or your opponents).
Try to own fewer pawn islands than your opponent.
In an ending with two rooks versus rook and a pair of minor pieces, the side with the minor pieces should keep rooks on the board.
In queening races: 1. Don't putz around! 2. Queen a pawn as fast as you can. 3. Slow down your opponent's queening attempts as much as you can.
A knight ending is the closest thing to a pure king and pawn ending.
A bishop is of greater value than a knight in queening races because a bishop can perform both defensive and offensive duties, while the knight is capable of only one or the other.
If you have a passed pawn and your opponent does not, exchange for an endgame.
Pawn captures towards the center.
Avoid creating holes in your position. Occupy your opponent's holes with pieces.
Attack at the pawn chain’s base rather than at its head.
If attacking on the wing then close the center.
If defending, then open the center or seek counterplay in the center.
When playing against an isolated pawn trade pieces and centralize.
When playing with an isolated pawn play for attack against the opponent's king.
Chip away at the opponent's center from the sides if he has a space advantage.
Centralize pieces and redeploy unemployed pieces.
If ahead in material, swap pieces but not pawns. If behind in material, swap pawns (not pieces) and complicate.
A knight on the rim is dim.
In a winning position avoid unnecessary complications. When losing take wild chances and complicate at every opportunity.
Trade opponent’s active and centralized pieces.
Tie your opponent’s pieces down to his pawns (or king).
Don't play passively. Seek out activity. Masters focus on gradually improving their positions to convert.
When your opponent is tied down or in a bind and is just waiting: look for ways to improve your position without giving him any counterplay.
In a winning position if the opportunity arises to simplify and retain equally or better winning chances, then make the simplification.
Avoid unnecessary retreats or decentralizations in an open position.
Don't capture a pinned piece unless there is a concrete gain from it.
Welcome confrontation when your pieces are better posted than the opponent's. Don't create confrontation if you are the one lagging in development or the confrontation would reside on your opponent's strong wing. Engage the opponent in confrontation when he is unprepared for it.
The player who holds a temporary advantage must create confrontation or attack, otherwise the advantage is lost.
When attacking avoid swapping or retreating pieces.
Maintaining a lead in development is more important than keeping the two bishops.
Don't allow the opponent to eliminate key defenders of your king.
If cramped then trade pieces; if you have a space advantage then avoid exchanges unless they favor you.
If you are cramped and have a freeing break, then play it.
Avoid opening the position on the wing where your opponent has more space.
The player with less space only rarely gets an attack going.
Minor Piece Imbalance
In a closed position knights tend to favor bishops; in an open position bishops tend to favor knights.
If in possession of the bishop pair when your opponent is not then avoid exchanging bishops. Open the game and play for an asymmetrical fluid pawn structure (i.e. the Bishop pair is more effective when the pawn structure remains fluid – not fixed).
If in possession of only one bishop then place your pawns on the opposite color.
If position is closed when in possession of the two bishops, open up the position to give them more space.
Opposite colored bishops favor the attacker.
When in possession of both bishops, and your opponent only one, place your pawns on the same color as the opponent's remaining bishop. Fix your opponent's pawns on the same color as his remaining bishop.
When strong on one color then play on that color.