Initiative
Active play aimed at creating threats against the opponent, cramping their position, and restricting the mobility and options of their pieces.
The initiative matters enormously in chess. How an initiative grows is closely tied to strengthening piece coordination and to disorganizing the opponent's forces. To seize the initiative, a player can accept positional concessions or material sacrifices.
To judge an initiative correctly you have to weigh how solid it is and how long it will last, since an initiative can prove temporary and gradually fade. The best way to neutralize it is a counterattack.
