"Called it quits" origin

What is the origin of the phrase “called it quits”?

According to the OED, it’s from 1473:

The definition of quits had variations over the centuries; the OED gives the first use of the phrase as 1851. This clearly derives back to the 1478 definition.

We couldnt call it love cause it really wasnt love anymore
Yet we couldnt call it hate cause theres no way to hate
Someone youve loved so much before We couldnt call it livin cause it wasnt still alive
We couldn`t call it dead cause it refused to die
We ran out of anything to call it so we called it quits

Bill Anderson, 1971