CONTENTS

C. General Rules and Technical Recommendations for Tournaments / 04. FIDE Swiss Rules / C.04.5 FIDE-approved Accelerated Systems / C.04.5 FIDE-approved Accelerated Systems (effective till 30 June 2025) /

C.04.5 FIDE-approved Accelerated Systems (effective till 30 June 2025)

In Swiss tournaments with a wide range of (mostly reliable) playing strengths, the results of the first round(s) are usually quite predictable. In the first round, only a few percent of the games have a result other than "win to the stronger part". The same may happen again in round two. It can be shown that, in title tournaments, this can prevent players from achieving norms.

An accelerated pairing is a variation of Swiss pairings in which the first rounds are modified in such a way as to overcome the aforementioned weaknesses of the Swiss system, without compromising the reliability of the final rankings.

It is not appropriate to design an entirely new pairing system for acceleration, but rather design a system that works together with existing FIDE-defined pairing systems. This result is normally achieved by rearranging score brackets in some way that is not only dependent on the points that the players have scored. For instance, one of the possible methods is to add so-called "virtual points" to the score of some higher rated players (who are supposedly stronger) and henceforth build the score brackets based on the total score (real score + virtual points).

The following chapters will describe the methods that were statistically proven to accomplish the aforementioned goals. The Baku Acceleration Method is presented first, because it was the first that, through statistical analysis, was proven to be good and stable (and is also easy to explain).

Other accelerated methods may be added, as long as they can be proven, through statistical analysis, to get better results than already described methods or, if their effectiveness is comparable, to be simpler.

Unless explicitly specified otherwise, each described acceleration method is applicable to any Swiss Pairing System.

C.04.5.1 Baku Acceleration

Premise

The Baku Acceleration Method is applicable in any tournament where the standard scoring point system (one point for a win, half point for a draw) is used.

Initial Groups Division

Before the first round, the list of players to be paired (properly sorted) shall be split in two groups, GA and GB. The first group (GA) shall contain the first half of the players, rounded up to the nearest even number. The second group (GB) shall contain all the remaining players.

Note:

for instance, if there are 161 players in the tournament, the nearest even number that comprises the first half of the players (i.e. 80.5) is 82. The formula 2 * Q (2 times Q), where Q is the number of players divided by 4 and rounded upwards, may be helpful in computing such number - that, besides being the number of GA players, is also the pairing number of the last GA player.

Late entries

If there are entries after the first round, those players shall be accommodated in the pairing list according to C.04.2.B/C (Initial Order/Late Entries).
The last GA-player shall be the same as in the previous round.

Note 1:

In such circumstances, the pairing number of the last GA‑player may be different by the one set accordingly to Rule 2.

Note 2:

After the first round, GA may contain an odd number of players.

Virtual points

The "accelerated rounds" are the ones in the first half (rounded up) of the tournament.
Before pairing the first half (rounded up) of the accelerated rounds, all the players in GA are assigned a number of points (called virtual points) equal to 1.

Such virtual points are reduced to 0.5 before pairing the remaining accelerated rounds.

Note:

Consequently, no virtual points are ever given to players in GB, or to any player after the last accelerated round has been played.

Example:

In a nine-round tournament, the accelerated rounds are five. The players in GA are assigned one virtual point in the first three rounds, and half virtual point in the next two rounds.

Pairing score

The pairing score of a player (i.e. the value used to define the scoregroups and internally sort them) is given by the sum of his standings points and the virtual points assigned to him.