From Ranking to Seeding to the Shape of the Draw
The ranking's practical function is administrative. It determines who gets into which tournaments, who has to qualify, who is seeded and where the cut-off lines fall for entry lists. Seeding then shapes the tournament itself, because seeds are distributed through the draw so the highest-ranked players cannot meet in the early rounds. A seeded player faces unseeded opponents first; an unseeded player may face a seed immediately.
That produces a cliff edge rather than a smooth gradient. The difference between the last seeded position and the first unseeded one is a small gap in ranking and a large gap in the expected difficulty of a first-round match, and the effect propagates, since an easier early draw makes a deeper run more likely, which produces more points, which improves the next ranking. Positions near a seeding cut-off are worth defending far beyond what their numerical distance implies, and that is where a great deal of late-season scheduling effort quietly goes.
