I see that 50% of the challenges currently open for submission require a previous first place challenge finish. It's OK to have challenges of that sort, but in my opinion not quite as high a percentage; after all how does one finish first without being allowed to enter? Opinions?
This issue has been debated many times in the Forum way back two years at least. Browse it if you have time to waste, you may find yourself laughing.
Check previous Challenges where this "only entrants who have won at least one photo challenge" rule applies, and you will see that a big percentage of the participants in these challenges never won a challenge before, so it is really up to you. Really, I dought the host ever checked or respected her\his own creation.
But, "I might consider allowing entries from beginner participants if their shot are on par with the rest of the entries." In other words, the host decides, so again, it is up to you.
Opinions? It is nothing short of pompous and slightly arrogant. Many members deters from participating in DPchallenges because many hosts are simply not up to the challenge.