This is a combination of several factors which makes up the most common name possible. It includes whether the most occurrences per letter are vowels or consonants (I.e. vowels only comprise 32-38 of first letters of countries). Also, even if there is a more popular letter for a certain space, if it is not the write type of letter (vowel/consonant) it cannot be accepted. 4 letters share the first part, the letter with the largest country is given. This is the same case for the third and fourth letters.