Explanation
The Tournament Pairing Number (TPN) is a pairing number, not the player's current place in the standings. Under FIDE's general rules for individual Swiss tournaments, a format where opponents are paired round by round, participants are ordered before round one first by strength, usually rating, a numerical estimate of competitive playing strength; then by FIDE title, such as Grandmaster or International Master; and then alphabetically, unless another criterion was announced. The highest participant in that order receives TPN 1, the next TPN 2, and so on.
The TPN then acts as a stable input to the pairing algorithm. In the FIDE Dutch system, for example, players are ordered for pairing first by score and then by ascending TPN. The number can also appear later in color-allocation rules.
Initial TPNs can be provisional when there are late entries. FIDE allows reassignment when the participant list closes or when data used for the initial order are corrected, subject to rule-defined timing limits. A TPN therefore should not be read as a performance ranking that changes after every round.
Common confusions
TPN vs. standings position
The TPN comes from the initial pairing order and normally stays stable. A standings position depends on tournament results and can change every round.
TPN vs. rating
Rating usually helps create the initial order, but the TPN is the tournament number produced from that order. It is not itself a strength measurement.
