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Anti-Dumping Methods

One of the great concerns in running RR qualifiers is the potential for "Dumping," that is deliberately losing a match either to benefit friends or to prevent a more dangerous team from qualifying. Various methods have been proposed in other threads to mitigate this: careful scheduling, revised carryover procedures are two.

Careful Scheduling

One clear issue is to have teams from the same country or the same zone play early. This is clearly possible for the zones with relatively few entrants: North America, Asia-Pacific, South America, etc., but probably impossible for Europe. 

The more important problem is to have late matches between teams that have self-interest predominating over other concerns. Self-interest would include position among qualifiers and whether the team qualifies or not. Another way to have self-interest predominate would be to change the carryover structure so that doing well in every match is important in the KO phase of the event. A key point is not to have late matches between an uninvolved team and a team on the bubble for qualifying. 

Various people have asserted that one can proceed without advance scheduling. But I know from experience that one can get towards the end and have a situation with two rounds to go where A and B still need to play each other and both A and B still need to play C. What I don't know is how far from the end of the event there is still sufficient freedom to avoid this type of situation. 

Carryover

Another way to combat dumping is to have the results from the RR affect the KO matches. At the moment the only meaningful issues are relative position and match score - and the carryover is severely limited. 

One suggestion made elsewhere is to make the carryover solely dependant on the VP scores of the two teams. Thus if one team scored 280, the other 250, the carryover would be some function of the 30VP differential.

I offer the following:

The match winner carries forward the VP differential from the match as a number of imps. Thus a win by 20, which is 15-5 in VP, would become 10 imps, 40 imps, which is 18.09-1.91 in VP would become 16.18 imps, a blitz - 60+ imps - would be cut to 20. The leader in VP from matches against all other teams carries forward the difference in VP times the ratio of their VP to the total scored by both teams as imps. To use a concrete example, consider US1 vs Canada.

Canada beat US1 by 5 imps, or 11.48 - 8.52 in VP. This would give Canada 2.96 imps

US1 scored 293.89VP total, Canada 243.22. Backing out the direct match leaves US1 285.37VP, Canada 231.74.

53.63, the difference in VP in the other matches, would be multiplied by the ratio 285.37/517.11. This would give US1 29.60 imps. 

The net would be US1 26.64 imps. 

Or consider US1 vs Italy. Match score US1 +17 imps or 14.39 to 5.61. 8.78 imps to US1.

Other match scores: US1 279.50, Italy 278.98. The .52 difference would be reduced to .26. Net carryover, US1 gets 9.04.

Using the VP differential from the head-to-head match caps the carryover from the match at 20 imps. Adding some function of the VP difference from other matches makes all matches important. Whether it should be as much as about half, as I have here, or say 30%, is a matter for reasonable discussion. 

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