Develop the Pieces
Playing a chess game is similar to coaching a sports team. You don't actually expose yourself to physical injury, but you do decide what your players will do. Your team in chess is not made of people, however. Rather, it is made of pieces and pawns.
Team Sport
So think of a team sport. Anything you prefer will do: football, soccer, hockey, or basketball. Any sport that pits a group of players against another group of players will be appropriate.
Let's take basketball for example. You are sending five players against the enemy five to score more points. So what do you think of this strategy: Send your best scorer out against the other team while the rest of your players watch the action?
It doesn't take a genius to figure out that such a strategy will not work very well. In fact, it's so bad, no coach will even think of trying it. Yet that is the very strategy many inexperienced chess players go for after learning of the tremendous power of the queen. Yes, she is strong, but she cannot do it all by herself.
A famous case of a player with a big lead in development (and, incidentally, controlling the center) carrying out a successful attack is Legal's Mate. This trap is named after De Kermur, Sire de Legal, a strong eighteenth-century player.
1. e4 e5 2. Nf3 d6 3. Bc4 a6 4. Nc3 Bg4.
Black has moved only pawns and now brings out a bishop where it is undefended. White has developed and played to control the center.
5. Nxe5! Bxd1 6. Bxf7+ Ke7 7. Nd5 checkmate.
Three minor pieces and a pawn control the center and combine in checkmating the exposed Black king.
Build up Power
Since greater force generally defeats lesser force, and since you cannot gain greater force immediately against an experienced opponent, you will need to build up your force gradually. The way to do that is to develop a new piece with each move.
The trouble with the losing strategy in Legal's Mate is that Black only developed one piece during the entire game: The bishop moved to g4 and captured a queen. All the rest of Black's moves involved pushing pawns or getting the king out of check.
Meanwhile, White developed first a knight, then a bishop, then another knight, and finally began a powerful attack using those pieces and his control of the center. It's a clear case of what they call in basketball a three-on-one break.
Moving the Same Piece Again
A very good principle to keep in mind whenever you play a chess game is to move a different piece each time it is your move unless there is a particularly strong reason to move one you have already brought out. Then your problem becomes one of finding those strong reasons when you need to. These include:
You will lose a piece or pawn if you don't move a developed piece.
You can begin a winning attack by moving a developed piece.
You can force your opponent to abandon his plan of attack by making a threat with a developed piece.
There are no undeveloped pieces left to move.
A very good short-term goal to shoot for in the early part of the game is to connect your rooks. That means empty out the squares between your rooks on the first rank if you are White or on the eighth rank if you are Black. You can begin this by bringing out your minor pieces so that they control the central squares. Next, you can castle. That will connect your rooks and leave your king safe.
Both sides have developed pieces and castled.
Developing pieces means not just getting them off their original position. It also means putting them where they will do some good. So you have to have a pretty good idea where that will be.
Long-Range Pieces Need Open Lines
Bishops, rooks, and queens won't ever do you any good unless they can oversee open lines. Any that sit behind friendly pawns represent unused potential. The thing to remember about them is that the bishops can come out into the melee early, while it is generally a good idea to hold back a bit on bringing out the rooks and queens.
The reason is simple. Bishops are less valuable than the major pieces, so can be exposed earlier. Also the rooks are a bit awkward with many pieces and pawns crowding the board. They are at their best later in the game when many pieces have been exchanged. The more ranks and files open up for them, the better off they are.
White to move. Look at the White long-range pieces and note how many squares they control.
Fianchetto
Fianchetto is an Italian word meaning “flank development.” It refers to the development of a bishop at g2, b2, b7, or g7. These squares are near the side of the board, but from them, the bishop commands one of the longest diagonals. Fianchettoed bishops control the center from the side of the board.
The problem with a fianchetto development is that an extra pawn move has to be made to make room for the bishop. This can cause problems, particularly if your king is nearby after castling.
Both sides have fianchettoed their bishops on the kingside.
Knights Need Outposts
An outpost is a square in or near the center that is protected by a friendly pawn. This is an ideal square for a short-hopping knight. Even better is a hole, which is an outpost in the opponent's territory that cannot be assailed by an enemy pawn.
The knight on e5 is occupying an outpost. The knight on e4 is in a hole.
Keep in mind that minor pieces, and major pieces as well, need secure squares in order to function properly. If your opponent can drive your piece away from its open file, diagonal, or outpost with a pawn, or by attacking it with a piece where it cannot be defended, your piece is not secure.

