Mathew Knowles is giving 100% of the credit to Beyoncé for her 'Album of the Year' win at the Grammys -- saying it has nothing to do with Jay-Z's complaints last year about her not already having that gong on her mantel yet.

MK tells TMZ those criticizing Bey's win and chalking it up to Jay-Z clearly don’t get how the Grammy voting process works -- and then goes on to break the whole thing down for us.

Mathew -- who’s been a voting member for 17 years and is on the Grammy board that picks the nominated albums -- tells us they listen to thousands of songs, including full albums.

Then, they debate which albums should be nominated, and it’s up to the voting members to decide the winners.

So, Mathew makes it clear -- Bey’s win was all about her album being the best body of work, not because of Jay-Z’s complaints last year about her breaking records but still missing out on the crème de la crème, Album of the Year.

Of course, last night was huge for Bey -- she didn’t just snag AOTY, she also picked up Best Country Duo/Group Performance with Miley Cyrus, and made history as the first Black woman to win for a country album.