This method does not always work out well, but here is an example of a new writer writing a spec script around a well-known property without the rights, and therefore, placing a bet that he would be able to get the script into the hands of a high-profile producer who would then help secure the proper rights. Sometimes this method can work. At other times, the parties may receive a "Cease & Desist" order from the rights holder's attorney. There is no one size fits all. I'd estimate this method typically has a higher chance of success when the property is ubiquitous, when you are indeed able to attach a big name - a game changer, and when the rights holders are inherently motivated to act on the rights.
Newcomer Evan Romansky penned the spec script, which was given to Murphy via his agent at CAA. Murphy spent a year securing rights to the character and the estate of original producer Saul Zaentz.http://www.hollywoodreporter.com/live-feed/one-flew-cuckoos-nest-prequel-ryan-murphy-scores-two-season-order-at-netflix-1036041?utm_source=Sailthru&utm_medium=email&utm_campaign=THR%20Breaking%20News_now_2017-09-06%2016:04:56_lgoldberg&utm_term=hollywoodreporter_breakingnews