Tempo
A tempo is a single move counted as a measure of time: gaining one means making a useful move that also forces the opponent to react, while losing one means spending a move that accomplishes nothing.
Chess is a race, and each move you make is a tempo that you spend. Whoever uses their tempi on useful moves, such as developing a piece or creating a threat, pulls ahead in that race. Whoever wastes them on moving the same piece twice in the opening, or on a pawn push with no purpose, falls behind.
You gain a tempo when you make a move that your opponent must answer by retreating or by moving a piece to a worse square, while your move was one you wanted anyway. For example, attacking a developed piece with a pawn that you wished to advance forces it to lose time. You lose a tempo when you drag a piece to a square and then have to move it again.
Tempo matters most where the game is sharp: in the opening, in attacks against a king, and in pawn races. In many endgames the exact count of moves decides the result, and there the question becomes who has to move.
A common mistake is to chase a tempo at any cost. A move that wins time but damages the pawn structure or loosens the king may cost far more than it earns, so measure the gain against the concession.
Strategic ideas such as "Tempo" show up in your games as small decisions, move after move. A first lesson with George Li reviews those decisions and turns them into a study plan.
Related terms
Initiative is being the side that makes the threats and sets the pace of play, so the opponent spends their moves answering instead of pursuing their own plans.
Development means bringing your pieces from their starting squares to active posts, usually by moving the knights and bishops out, castling and linking the rooks, so they can all contribute to the fight.
A lead in development means having more of your pieces already active than your opponent has at the same moment, which usually gives a short window to open the position and attack before they catch up.
Piece activity describes how much influence a piece exerts, measured by the squares it controls, the targets it eyes and the freedom it has to move, so an active piece is worth more than its nominal value.
A reserve tempo is a spare, harmless move, usually a pawn move, that one side can make without damaging its position, passing the obligation to move across to the opponent.
Opposition is a standoff between the two kings on one file or rank with a single empty square between them; whoever does not have to move holds it, because the other king must give up ground.
Guides that go further
What to decide first, the questions to ask, what a first lesson should show and the red flags to avoid.
How much does chess coaching cost?
Published rates for private, group and subscription chess coaching, with the source and the date of each.
A game review, a read on your level and a written study plan from George Li.
Want to spot this in your own games?
A first lesson starts with your games: George reviews them and builds a study plan around what he finds.