||This article includes a list of references, but its sources remain unclear because it has insufficient inline citations. (February 2011)|
A Googlewhack is a type of contest for finding a Google search query consisting of exactly two words without quotation marks, that returns exactly one hit. A Googlewhack must consist of two actual words found in a dictionary. A Googlewhack is considered legitimate if both of the searched-for words appear in the result page.
Published googlewhacks are short-lived, since when published to a web site, the new number of hits will become at least two, one to the original hit found, and one to the publishing site.
The term Googlewhack first appeared on the web at UnBlinking on 8 January 2002; the term was coined by Gary Stock. Subsequently, Stock created The Whack Stack, at googlewhack.com, to allow the verification and collection of user-submitted Googlewhacks.
Since 2003, British comedian Dave Gorman has toured the United Kingdom, France, China, Australia, Canada, and the United States with a comedy tour entitled Dave Gorman's GoogleWhack Adventure and has published a book of the same name. These were based on a true story. While attempting to write a novel for his publisher, Gorman became obsessed with Googlewhacks and travelled across the world finding people who had authored them. Although he never wrote his novel, he did eventually write a book about his "Googlewhack Adventure" which went on to be a Sunday Times #1 best seller in the UK and has also been published in the U.S. and Canada. A translation is in the works for Japan.
Participants at Googlewhack.com discovered the sporadic "cleaner girl" bug in Google's search algorithm where "results 1-1 of thousands" were returned for two relatively common words such as Anxiousness Scheduler or Italianate Tablesides.
Googlewhack went offline in November 2009 after Google stopped providing definition links. Gary Stock stated on the game's web page soon afterwards that he was pursuing solutions for Googlewhack to remain viable. However, the game has not come back into play, and there is no word of when or if that will happen.
Some people propose the googlewhack "score," which is the product of the hits of the individual words. Thus a googlewhack score is highest when the individual words produce a large number of hits.
New Scientist has discussed the idea of a Googlewhackblatt, which is similar to a Googlewhack except that it involves finding a single word that produces only one Google result. Lists of these have become available, but as with Googlewhacks they result in the Googlewhackblatt status of the word being destroyed - unless it is blocked by robots.txt or the word does not produce any Google results before it is added to the list, thus forming the Googlewhackblatt Paradox. Those words that do not produce any Google search results at all are known as Antegooglewhackblatts before they are listed - and subsequently elevated to Googlewhackblatt status if it is not blocked by robots.txt.
One way a Googlewhackblatt's status can be ruined is when an entirely unrelated website including the word is created. An example of this is the nonsense word "Bumruff" which originally returned a single result (the surname of a woman living in Ireland in 1911), but once a person on Xbox Live chose the name as a Gamertag, the word's status as a Googlewhackblatt was destroyed.
Feedback stories are also available on the New Scientist website, thus resulting in the destruction of any existing Googlewhackblatts that are ever printed in the magazine. Antegooglewhackblatts that are posted on the Feedback website become known as Feedbackgooglewhackblatts as their Googlewhackblatt status is created. In addition, New Scientist has more recently discovered another way to obtain a Googlewhackblatt without falling into the Googlewhackblatt Paradox. One can write the Googlewhackblatt on a website, but backwards, and then search on elgooG to view the list properly while still keeping the Googlewhackblatt's status as a Googlewhackblatt.
In contrast to Googlewhacks, many Googlewhackblatts and Antegooglewhackblatts are nonsense words or uncommon misspellings that are not in dictionaries and probably never will be.
The probabilities of internet search result values for multi-word queries was studied in 2008 with the help of Googlewhacks. Based on data from 351 Googlewhacks from the whackstack, the Heaps' law coefficient for the indexed World Wide Web (about 8 billion pages) was measured to be . This result is in line with previous studies which used under 20,000 pages. The googlewhacks were a key in calibrating the model so that it could be extended automatically to analyse the relatedness of word pairs.
- Hapax legomenon
- Statistically Improbable Phrases – finds phrases in Amazon books unlikely to appear in any other book indexed
- Googlewhack official rules
- Googlewhack NACK!
- Anxiousness Scheduler
- italianate tablesides
- googlewhack scoring is discussed numerous places, e.g.,:   
- Archival References to Web Pages, Ninth International World Wide Web Conference: Poster Proceedings (May 2000)
- Lansey JC, Bukiet B (January 2009). "Internet Search Result Probabilities, Heaps' Law and Word Associativity". Journal of Quantitative Linguistics 16 (1): 40–66. doi:10.1080/09296170802514153.
- Googlewhacks for Fun and Profit Google Tech Talk 2008
- Poster Presentation
- Ricardo Baeza-Yates and Berthier Ribeiro-Neto, Modern Information Retrieval, ACM Press, 1999.
- Bowman, Lisa M (29 January 2002). "Have you Googlewhacked?". CNET News. Retrieved 2012-12-31.
- "'Googlewhacking' a new activity for the searchers". London: Reuters. 6 February 2002.