doggedness vs persistency

doggedness and persistency both are nouns.

Word	Noun	Adjective	Verb	Adverb
doggedness	Yes	No	No	No
persistency	Yes	No	No	No

As nouns, doggedness and persistency are synonyms defined as:

Other synonyms of doggedness include perseverance, persistence, pertinacity, tenaciousness, tenacity.

doggedness (noun)	persistency (noun)
persistent determination	persistent determination