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Positioning Seeds

A seeding policy specifies how many seeds to allow per draw size and how seeds are to be positioned within a draw structure; it may also instruct generateDrawDefinition to disallow the placement of seed numbers in positions which are not defined as seeded positions, as well as indicate that duplicate seed numbers may be used.

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    • "My Org Policy"
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        seedingProfile​

        There are two seedingProfile patterns supported for elimination structures: "CLUSTER" and "SEPARATE". seedingProfile.positioning determines which draw positions appear in seedBlocks.

        "CLUSTER" indicates the positioning used by the ITF, while "SEPARATE" indicates the positioning used by the USTA.

        In ITF draws, seeded posiitions can appear next to each other (though the positions are part of different eights, for instance). In USTA draws there is always an even separation, with seeded positions in the top half of of a draw at the top of position groups, and seeded positions in the bottom half of a draw at the bottom of position groups.

        seedingProfile.groupSeedingThreshold will set seedValue to lowest value within all groups where seedNumber is > threshold

        Seed Blocks​

        A Seed Block is a grouping of positions used for placement of seeded participants. For a typical ITF elimination structure with a draw size of 32, the seed blocks follow the pattern:

        [1], [32], [9, 24], [8, 16, 17, 25], ...

        The first and second seeds are always in their own seed block, which means participants with these seed assignments have fixed positions. The third and fourth seeds are in a seed block together; the positions within the block are assigned at random to the seeded participants. The fifth through eighth seeds have a block of four possible positions, and so forth.

        seedCountThresholds and drawSizeProgression​

        Objects in the seedCountThresholds array determine seedsCount, the number of seeds which are allowed for each drawSize, by defining a minimumParticpantCount.

        • When drawSizeProgression is true, thresholds for smaller drawSizes are applied to larger drawSizes.
        • When drawSizeProgression is false it is possible to have more granular control of the policy for each drawSize.

        duplicateSeedNumbers​

        Some providers prefer for participants in a seedBlock such as [5, 6, 7, 8] to all appear with the same seedValue. This implies that even though seedNumbers may be assigned by ranking or rating, participants within a seedBlock should be considered equal.

        { duplicateSeedNumbers: true } allows auto seeding methods to randomly select the order in which participants in a seedBlock are placed. For standard Elimination structures this is meaningless, but in Round Robin and Staggered Entry structures particpant placments can vary.

        Seed Assignments​

        Every draw structure uses seedAssignments to associate unique participantIds with unique seedNumbers.

        note

        Only one participantId may be assigned to each seedNumber, but each seed assignment may have a custom seedValue. This supports scenarios where the fifth throught the eighth seeds appear with a value of '5-8'; some providers even choose to display numerous participants with the same seed number on a draw... if five particpants have equivalent rankings they could all appear as seed "4", even though one of those five would get a position from the 3-4 seedblock and four of the five would be assigned positions from the 5-8 seed block.

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