During the middle-game the number of possible positions is so large that well defined principles won’t work. The opening principles literally tell us what to move, where to move it and when to move it. During the middle-game, we rely on generalized principles that give us a broader idea of what to do in a given situation. The goal of the middle-game is to gain a material and positional advantage going into the the endgame. There are many ways to reach this goal and how you achieve it depends completely on the position. As with the opening, any move made during this phase of the game should be guided by a middle-game principle. Refer to these principles until you have them committed to memory.
Evaluation Before Planning
Always evaluate a position before creating a plan. You need to know exactly what’s going on within a position before you can create a plan of action.
King Safety and Mobility Come First
If your King is safe, your pieces can go on the offensive and attack. However, pieces need mobility to attack, so always mobilize your pieces. Always make sure your King is safe before attacking your opponent’s position.
The More Active a Piece, The More Power it Has
When a piece is active, it controls or attacks a large number of squares. The greater the level of activity, the more power a piece has. Pieces are most active when positioned centrally. Always look for ways to activate and further activate your pieces, especially towards the center.
Be Ready to Develop Rapidly to Any Part of the Board
One of the reasons pieces have greater power when centrally located is because they have greater mobility. Centralized mobility gives a piece the ability to move to one side of the board or the other quickly. If it’s needed to suddenly help with an attack or defend a position elsewhere, it can rapidly respond. Move pieces to squares that allow them access to to any part of the board.
Always Count Attackers and Defenders and Compare Their Relative Value
Always count the number of attackers and defenders before committing to an attack. Then compare their individual relative values. You’ll want to have more attackers than defenders when attacking and more defenders than attackers when defending. However, compare the relative value of the individual pieces involved to make sure you’re not going to lose material when the exchanges start.
Start the Exchange of Material with the Unit of Least Value
When exchanging material during an attack, start the exchange with a piece of lesser or equal value first. Never start an attack with a piece worth more than the target piece unless you’re sacrificing that piece.
Never Capture Pawns and Pieces Unless it Helps Your Position
Never consider attacking or capturing a piece, regardless of the material gain, if it weakens your position. A weakened position is harder to correct than a material imbalance.
Repair Weaknesses Before Attacking
If you have a weak point in your position, try to strengthen it before considering an attack. Weaknesses are a long term liability.
Exchange Pieces When it Helps Your Defense
Sometimes, you’ll end up with a middle-game position in which your own pieces get in each other’s way. This means that some of your pieces have limited mobility. If you exchange the blocking pieces with enemy pieces (as long as the exchange is balanced) you free your blocked in pieces and remove a few potential enemy attackers from the fight.
Put Rooks on Open Files
Rooks are great for controlling open files. If you see an open files and have an available Rook, put that Rook on the open file.
Consider Your Pawn Structure Before Making Any Pawn Move
Before moving a pawn, determine if doing so will weaken that pawn or weaken the surrounding pawn structure. Weak pawns have to be defended by pieces, which takes those pieces out of the fight.
Make Pawn Moves to Open Up Lines
The opening principles tell us not to make too many pawn moves at the start of the game. While we’ve mobilized our pieces during the opening, we want to be able to further mobilize our pieces during the middle-game. Make pawn moves that open up lines for your pieces.
Be Aware of Counterattacks
Beginner’s often build up what looks like a winning attack. All their pieces are correctly lined up and they’ve carefully thought things through. However, they’ve forgotten to do one thing, look at their own position to see if their opponent has a counterattack that will do more damage. Always examine your opponent’s position for possible counterattacks before launching your own attack.
Exchange Material to relieve Positional Pressure
There are times when your opponent will have a large number of pieces amassed on your side of the board, giving your opponent attacking options. You may not be able create an adequate defense in time to stop the attack. However, if you could immediately exchange some of your pieces for theirs, you’d weaken the attack and relieve the positional pressure. When enemy pieces are putting your position under pressure, exchange material to relieve that pressure.
Use Knights in Closed Positions and Bishops in Open Positions
Bishops are long distance pieces and need mobility to be useful during the game. When the position is open, with diagonals void of pawns and pieces, the Bishop should be used over the Knight. When the position is closed, there’s not a lot of room for long distance attackers to move. This is where the Knight is extremely powerful because of its ability to jump over pawns and pieces. In close positions, the Knight is more valuable than the Bishop.
Don’t Defend a Weak Point if it Ruins Your Game
The are time when you simply cannot defend a weak point in your position. There may be too many attackers or defending the weak point might create additional weak points. If a defensive position is hopeless, move on and further strengthen the rest of your position.