Posted 2006-November-16, 23:34
A = top third of field
B = Middle third
C = lower third
Example : Lets say, for arguments sake, that exactly 30 pairs sign up. So we have 1 section, 15 NS pairs and 15 EW pairs. The field has 30 pairs and we'll have 10 As, 10 Bs, 10 Cs.
Lets say, again, for arguments sake, 10 pairs have at least one star, 10 have exactly 1000 ACBL MPs, and 10 have 100 ACBL mps.
The star pairs (top third) are put into A. The 1000-MP pairs into B. The 100-MP pairs into C.
The pairs are then divided evenly between NS and EW. So NS will have 5 stars, 5 1000-mps, 5 100-mps. Likewise EW.
Finally, the NS pairs are scrambled so the starting table for each pair is unpredictable.
Similarly EW.
In practice things are not so clean cut. Some players won't have any ACBL points. Some will have BBO points from (say) SKY CLUB. Some wont have any points at all.
I try to solve this by assigning each player 'stratification points'. A pair gets the higher of the stratification points of the 2 players in the pair.
Star = some huge number of points (to force pair into A)
ACBL points = as is
BBO Points (used if no acbl points) are multiplied by some semi-arbitrary value , like 2 or 3
Level (used if no acbl, no bbo points) are used as a last resort
I'll emphasise, though; you don't need to worry about this. Yes, some people who would not have scratched will now scratch in B or C. But no one who would win points today won't win points tomorrow. Stratification only helps, it doesnt hurt.