Performance rating

A performance rating describes a performance, not a new permanent identity for the player. The Tournament Performance Rating (TPR) used by the International Chess Federation (FIDE) starts from the average rating of opponents actually played over the board and adjusts it according to the percentage score achieved. A rating is a numerical estimate of competitive strength; FIDE uses an Elo-type rating system.

The FIDE calculation first finds the Average Rating of Opponents (ARO). It then takes the fraction of points scored in those games and converts it, using the FIDE table, into a rating difference that can be positive or negative. That difference is added to ARO. At exactly a 50% score, the difference is 0, so TPR equals the opponents' average rating.

A high TPR means the tournament result was consistent with performing at that level against those opponents. It is not the player's new official rating and does not simply replace the previous rating. Official rating is updated through the rating system's own calculation. For FIDE rating-based tie-breaks, unrated participants also require special handling rules or the tie-break may have to be dropped.