User blog comment:B214/Question and Answers 3/@comment-4547267-20140720022758/@comment-77.253.97.42-20140721093133

@anon i dont remember any info in books about king piece but that piece is quite rare there are 2 times more rock bishops and knight and 8 times more pawns also at the promotion test ise comments that there were only few high class promotions so i believe it rare to become king