Average Tournament Performance Rating of Opponents

Average Tournament Performance Rating of Opponents, abbreviated APRO, describes how your opponents performed in the event rather than only what their ratings were at the start. A rating is a numerical estimate of competitive strength. A Tournament Performance Rating, or TPR, is calculated from the average strength of a player's opposition and the percentage of available points scored against it.

A TPR is first calculated for every opponent. The method of FIDE, the International Chess Federation, begins with that opponent's Average Rating of Opponents and adds or subtracts a rating difference corresponding to the fractional score. Fractional score means points scored divided by games played over the board. APRO then averages the TPR values of the opponents the participant faced and rounds to the nearest whole number, with 0.5 rounded upward.

A modestly rated opponent can therefore contribute a high TPR after scoring strongly against good opposition, and the reverse is also possible. This tournament sensitivity separates APRO from ARO, which only averages ratings, and from APPO, which uses the lowest rating compatible with each opponent's expected score.

Like every rating-based tie-break, APRO needs special rules when unrated players are present and is not recommended when the ratings used may change within the same event.