Thursday 18 March 2021


 With at least 2 sections of the 2021 O2C Doeberl Cup hitting the theoretical 'pairing limit', acceleration may have to be introduced into the pairings for the first time. For the uninitiated, the method used is to pair the top half of the tournament against themselves, and pair the bottom half in the same way.

However, there is a little more science to this, and even now, not all events do this correctly (eg Ballarat). The approved (Baku) method is to add a bonus point to the players in the top half for the first 2 rounds, and a half point to these players in the third round (NB for 9 round events it is 3 rounds with a bonus point, and 2 rounds with half a point). This method has been used at Hastings (where I was an arbiter), and no one seemed to even notice it was in use.

There are a couple of plusses and minuses which are worth noting. 

  • A player in the lower half can get to 3/3 without playing anyone seeded above them (rare but possible)
  • When the acceleration stops, the middle pairings look like round 1 pairings (although the gaps between seeds are a little smaller)
  • A number of lower half players can be on 2/3, while a similar number of top half players can still be on 1/3.
However, these do fix themselves up over the remaining (non-accelerated) rounds. And if the aim of acceleration is to find a clear winner by having the top seeds play each other earlier*, then it does work.

*I ran a test with a 64 player 6 round event, and the top 2 seeds met in round 5 with 4/4. Using the traditional method, this would be a round 5 paring with the players on 5/5.

1 comment:

Garvin said...

I would like to see more tournaments use the Baku acceleration system when fields have a high number of participants compared to the number of rounds, and especially when there is a large spread of ratings from top to bottom and a decent tail in the field