Many effective memorisers today resort to the "method of loci" to some degree. Contemporary memory competition, in particular the World Memory Championship, was initiated in 1991 and the first United States championship was held in 1997. Part of the competition requires committing to memory and recalling a sequence of digits, two-digit numbers, alphabetic letters, or playing cards. In a simple method of doing this, contestants, using various strategies well before competing, commit to long-term memory a unique vivid image associated with each item. They have also committed to long-term memory a familiar route with firmly established stop-points or loci. Then in the competition they need only deposit the image that they have associated with each item at the loci. To recall, they retrace the route, "stop" at each locus, and "observe" the image. They then translate this back to the associated item. For example, Ed Cooke, a World Memory Champion Competitor, describes to Josh Foer in his book "Moonwalking with Einstein" how he uses the method of loci. First, he describes a very familiar location where he can clearly remember many different smaller locations like his sink in his childhood home or his dog's bed. Cooke also advises that the more outlandish and vulgar the symbol used to memorize the material, the more likely it will stick.