Change in scoring system in the Olympiads

Change in the scoring ( and tie-breaking system ) for the chess Olympiads.

 Before the 38^th Chess Olympiad, the final results are decided by (1) points ( meaning game points and for a normal four-board format, this can take 0, 0.5, 1, 1.5 etc, up to 4. (2) Buch ( Buchholz score). This is the sum of your opponents’ scores in terms of points. (3) match points ( 2 for a win , 1 for a draw and 0 for a loss ).

 As an example, in the 23^rd Olympiad ( 1978 ), with 66 teams participating, Hungary won with 37 points from 14 rounds , while the Soviet team got 36. There is no tie, and so there is no need for using the Buchholz score. It is interesting to see that the Buchholz score for Hungary is 446.0 and that of the URS is 445.5, the tip of a whisker by any standard. In calculating this score, I notice that in the 14 opponents of each team, there are 8 overlaps. The mutual opponents in the different rounds included POL,NED,USA,ENG, BUL,GER, SWE and ISR. This can partly explain the small difference in the Buchholz scores. As a matter of contrast, if we use the Sonnenborn-Berger system of tiebreaking for team events, where you add up the products of game point (GP ) and match point of opponent (MP) for each team , the figure for HUN is 625.5 and that of URS is 605. The calculation for both teams is given below. They are big numbers because 14 rounds are involved.

 Scores for HUN:

Scores for URS:

 Using the post-2008 scoring criteria, both teams have 23 points ( 10 wins, 3 draws and no loss) creating a tie.The  SB score is required  as tiebreak. Hungary wins quite handily ( 625.5 to 605 ). FIDE prefers a further refinement where the lowest value of the products is discarded. So for HUN, it is 625.5-34 = 591.5 and 605-25.5 = 579.5 for URS, without changing the tiebreak result. This is called the Deducted Sonnenborn-Berger score (dSB) where the worst result is not included in the count.