Picture it. The FIA has just decreed that racing's top formula will now run with 2-litre engines. Instantly the field is open to a stack of small teams, and only Ferrari has prepared for it by building a race unit to the new formula. But that doesn't matter, because any race organiser who wants to can run an F1 race outside the championship and still attract star drivers.
That's a flavour of how it felt in 1961 when the new rules for grands prix, in an effort to reduce speeds after a rash of fatal crashes, specified 1.5-litre engines. It hadn't been too hard for a privateer team to get hold of a suitable engine for the previous 2.5-litre formula, but now many team managers realised they already possessed the goods to go grand prix racing.
Last year your 1500cc Coventry-Climax was an F2 engine; this season it's grand prix power. Ditto your Cooper or Lotus chassis. You might not expect to win, but you'd be in there with the big boys. And as long as the race organisers offered decent starting money, even the big boys would come to your non-title race.