when there where variation?What does the author mean?
Unchanged in 1400 years, the knight has had variations of the same shape,and has moved around the board in the same way
'Unchanged' means what it normally does. q=chess+knight&espv=210&es_sm=93&biw=1366&bih=633&source=lnms&tbm=isch&sa=X&ei=0ic0VNSqHqKM7Aa3rIBA&ved=0CAYQ_AUoAQ are some variations of the shape.
New words, one handy idiom, and a 2-minute quiz — delivered to your inbox to keep your streak alive.