If there's a competition on, then there will be a lot of plastic in the sky, up to cloudbase and within clouds that are sucking.
I've had that a while ago when flying to Berlin (VFR at 3000'-ish). There was a NOTAM about increased glider activity at a certain field which was at least 50km from my route. So that NOTAM went into the "garbage" department.
Turned out that their assignment for that day crossed my flight path. Actually one of their turning points happened to be one of my waypoints too. So all of a sudden I was confronted with at least 50 gliders, all at different altitudes, all crossing my flight path. Fortunately I was able to climb above the base of the clouds to remain clear but it was one of those ILAFFT moments...
My point here: why are the assignments, the actual routes that the gliders need to fly, not NOTAMed? Is it a timing issue where a NOTAM cannot be promulgated fast enough after the competition director decides on the route, or is it because they don't want to spoil the competition by releasing the route too early?
Even this would help me enormously:
E) INCREASED GLIDER ACTIVITY AT XXXX DUE TO GLIDING COMPETITION WITH 50+ GLIDERS PARTICIPATING. COMPETITION ROUTES UP TO 200 KM AWAY FROM XXXX ARE PUBLISHED EACH MORNING AT 0900LT. INCREASED GLIDER ACTIVITY CAN BE EXPECTED ON THESE ROUTES FM 1000' TO CLOUDBASE, FM 1100LT TO SUNSET. ROUTES ARE SET OUTSIDE CAS ONLY. MOST GLIDERS NOT TRANSPONDER EQUIPPED. FOR ACTUAL ROUTES CONTACT XXX INFORMATION ON YYY, CALL +XXXXXXXXXX OR [someurl].