Counting "Yan Tan Tethera"

Someone was telling me that in the 1950s he was in the Lake District and met a shepherd.  Sounded as though the man was a striking figure, with sheepskin coat and crozier (shepherd's hooked staff), counting the sheep with words like a children's counting rhyme.

This Wikipedia article, "Yan Tan Tethera," lists counting systems shepherds use to count sheep in many parts of the U.K.  The sequences of words also apply to counting stitches in knitting.

It's interesting to know traditional systems that are useful for keeping information straight without writing anything down.  Remember I noted Shakespeare's clown in A Winter's Tale who wanted some counters to calculate the money for fleeces?  The article discusses how the counting systems allow you to count up to twenty and keep score (a score was twenty; still is) by dropping counters in a pocket or moving a finger along notches marked on the staff.