How long does it take for a novice PD to become an "expert"? Once established, I would not expect an "expert" to fail yet considering the number of flippers (and PD's "excused") I think it happens far more often than one would expect.
Given that following this post a clarification was requested, I'll use myself as an example and try to answer landtuna's question above.
I began in radio in 1973, after four years in local television (both broadcast and local origination cable). I spent my first four years at a hybrid MOR/Classical station and worked practically every daypart and position. I was even the Public Affairs Director at one point, back when that title meant something.
In 1977, I was urged by the owner to take a position at an automated soft AC station in the same market because a sale was pending to the flamethrower top-40 AM and the owner thought I shouldn't get stuck knowing only one kind of music format. The joke was on both of us, as the station flipped to Beautiful Music after the sale and I was only kept on because I had thought to learn how to program the IGM automation system. Once they consolidated studios with both stations, all of us who had come along with the FM were summarily dismissed ("the AM guys can change the tapes on the FM.")
This is where luck enters the equation. When I became available, I was approached by a mom-and-pop operation in the market who wanted to make their AM/FM simulcast "more hip" (the AM had been all-news with the ill-fated News and Information Service from NBC, the FM had gone on the air only a couple years' previous with a badly done "contemporary MOR" format, and when NBC pulled the plug on NIS they started simulcasting). They had a clear vision of what they wanted: Contemporary, heavy on currents, targeted at 20- to 40-year-olds, no hard rock, no bubblegum, no novelty songs. And they thought hiring someone who had grown up in the market who was (barely) inside the demo to program the music was a good move, so they offered me the PD/OM position, even though I had never programmed before and it had only been five years since my first radio job.
This was a smaller market, and even if I knew what music research was, we certainly couldn't afford it. So I used the Whitburn books, arbitrarily rejecting anything that peaked below #10, eliminated the songs that weren't going to fit the "sound" the owners had in mind, added in a few dayparted songs that had been #1 or #2 on the Easy Listening chart, and then programmed the currents based on the Hot 100, eliminating the "don't fit" songs. It was research of a sort, I suppose, and like any PD I made decisions based on what songs were left after all my addition and subtraction.
I am convinced that the only reason it worked was because we were one of the first stations anywhere to do what came to be called Adult Contemporary. My competition on FM in-market was an automated top-40, an automated Country, and my former two stations. We had several Los Angeles stations which had in-market listening ... five were Beautiful Music,
one was the famous "mellow rock" KNX-FM, two AORs, one Classical, and two top-40s. And we were very successful for about three years until the owners sold out and retired. The new owners had their own ideas, and even though they offered to keep me on the changes they wanted to make just felt wrong, so I opted out. (I was later glad that I did, because they completely ruined the place and ended up in bankruptcy less than two years later.)
I'll summarize why I left my next gigs: Three were also from format changes by new owners, five were moving to larger stations from smaller ones, one was due to unresolvable personal conflicts between myself and a new GM hired after I had been with the station a while, and one was a breach of contract by the station.
I won't say I was perfect at all those gigs, but I was fortunate that my first station as PD did well in the ratings and I got a reputation as the "hot young programmer" and did well enough after that to be considered something of an "expert" (although, to be honest, I hate that word ... which is why, as noted by another poster, I don't use it very often in my posts here). Had that not been the case, I would never have hung out my consultant shingle after I left my last "on-hands" programming job.
So yes ... my first station was an "original idea" but it was the owners' idea, not mine. I just instinctively knew what to do with it. A lot of my "ideas" have been taken from other stations in other markets and tweaked to fit. Those of us who do this for a living know a good idea when we hear it and we also know when that idea may fit something we are doing.
Does that help?