Sturgeon's Law

90% of everything is crud.

This is Sturgeon's Revelation, but common usage has it that this phrase is what is meant when the Law is cited. The actual quote for the Law is, "Nothing is always absolutely so."

The first reference to Sturgeon's Revelation appears in the March 1958 issue of Venture Science Fiction, where science fiction author Theodore Sturgeon wrote:

""I repeat Sturgeon's Revelation, which was wrung out of me after twenty years of wearying defense of science fiction against attacks of people who used the worst examples of the field for ammunition, and whose conclusion was that ninety percent of SF is crud.""

There is also a (possibly apocryphal) story that tells of Sturgeon making the above comment during a panel discussion at a science fiction convention. When the audience protested, Sturgeon reportedly blinked and replied, "90% of everything is crud."

Sturgeon's Revelation is sometimes expanded as follows:
 * Corollary 1: The existence of immense quantities of trash in science fiction is admitted and it is regrettable; but it is no more unnatural than the existence of trash anywhere.
 * Corollary 2: The best science fiction is as good as the best fiction in any field. (Note: It is clear this doesn't necessarily follow from the Revelation- sci fi has minor advantages and disadvantages compared to other genres, and differing amounts of literature compared to other genres. If a thousand write sci fi, but a hundred thousand write real world, do the maths.)
 * Crawford's Corollary: Should you ever find that less than 90% seem to be crap, your standard is set too low and should be adjusted.
 * Critic's Corollary: 90% of people lack the taste necessary to distinguish between crud and non-crud.
 * Critic's Second Corollary: 90% of people will criticize 90% of what they see regardless of their ability to distinguish crud from non-crud.
 * TV Tropes Corollary: The difficulty of getting a group of people to agree on which 10% is not crud exponentially approaches infinity as the size of the group increases.  (Or, "Crud is in the eye of the beholder... so to speak.")
 * TV Tropes Second Corollary: The other 90% of crud is further divided into "Subjective Crud," "Crud You Like Anyway", and "Total Crud." The exact proportions of this division have never been researched, and most likely varies by the individual for reasons mentioned above.
 * TV Tropes Laconic Corollary: Ninety percent of Laconic Wiki articles are crud.
 * The Theorem of Narrow Interests: The more constrained the thing you're looking for, the fewer good examples exist.
 * Also: If a video game has user-created content, a large amount of it will be based on male or female genitalia or "LittleBigHolocaust."
 * Ruri's Law: "The vast majority of people are idiots". or, in other words, You're probably crud.

Sturgeon's Law is particularly obvious when the barriers to entry -- the whims of publishers -- are removed. Self-publishing, especially in the virtually cost-free environment of the Internet, makes the cruddy 90% visible to the public; it no longer languishes in an aspiring writer's desk drawer. This often leads to the false impression that Fanfic attracts poor writers; the fact is that the poor writers have always been out there, but until recently, their poor writing had few outlets to the public. As one writer put it, "flipping through Fanfiction.net is like flipping through hell with an occasional slice of the heavenly cheesecake thrown in."

If we assume that the 90% figure applies only to published works, then about one in a million of all things out there is not crud. Most people, though, have seen more than one non-cruddy thing in their lifetime.

Often the phrase is followed by the even more cynical addendum, "... including the other 10%." Rarely, a more optimistic second clause is added:

 "...but the remaining 10% is worth dying for."

A more ominous reading has it that Sturgeon's Law is a baseline. In other words, though at least 90% of a given thing is crud, it does not necessarily follow that the remaining tenth is all good. For a given subtype of medium, genre, etc., the percentage of crud may range from the minimum 90%, to 95%, to 99.99[vapor trail of 9s]%.

A related adage is employed by critic Yahtzee Croshaw, known as the Guantánamo Bay approach, who declares in one review that:

Everything is shit until proven otherwise

And in another review that:

Even if declaring a game to be shit after its first few hours of gameplay is perfectly professional, one should never assume that a game that starts out good will stay that way.

The Nostalgia Filter and Import Filter can be considered both side effects of this and a major balancing factor.

In person, Theodore Sturgeon didn't use the word 'crud' when this subject came up, in 1979. According to the Portland Pattern Repository, however, the true story is the opposite: Theodore Sturgeon said "crud", but the law is quoted using the word "crap".

There is a related principle actually observed in economics, the Pareto Principle or "80-20 rule": 80% of the work is done by 20% of the group. This makes sense if you think about it: in a given group there will be, for whatever reason, variation in the capability of its constituent individuals, and by and large, variation tends to take the form of a bell-curve distribution: the vast majority are average or near-average, with occurrence correlating to rarity. So, if you take that curve (representing the number of individuals at each level of performance) and multiply by said level of performance, you get a plot showing how the total amount of work done is distributed among the various levels of performance, which will obviously be skewing towards the higher-performance end. The rule is an approximation and the exact ratio will vary with the situation, but the general principle is very widespread in situations involving normal and power law distributions. The principal is also used in Statistical Process Control, a mathematical approach to quality control, stating that generally, 80% of total defects are caused by 20% of known failure modes.

May be Older Than They Think; Benjamin Disraeli wrote in 1870: "Books are fatal: they are the curse of the human race. Nine-tenths of existing books are nonsense, and the clever books are the refutation of that nonsense."

See also Sturgeons Tropes--tropes that aren't in and of themselves bad, but are usually done badly.