Donny Baseball is an interesting case, his career only lasted 14 seasons. At his peak he was great, maybe the best player in baseball for a few seasons, but back problems brought his stats down, so he doesn't have the counting starts that get you into the Hall.
I am tore on Mattingly, he was as good a player as there was for a few years, and I do think not getting to some artificial counting stat number is a lousy reason to keep a guy out of the Hall. But, then he was a Yankee.
He had 222 home runs, 1099 RBI and had a career slash line of .307/.358/.471. He was AL MVP in 1985, was named to 6 All-Star teams, had 9 Gold Glove and 3 Silver Slugger awards. Baseball Reference has him at a 39.8 career WAR.
This is his last time on the ballot. His first time, he received 28.2% of the vote, but it has been a downhill run from there. Last year he was only on 8.2% of the writers' ballots.
He should have cut those sideburns.