The next two on the list are Mark Grudzielanek and Mike Hampton. While both had nice careers, neither looks like a Hall of Fame type to me.
Mark Grudzielanek played middle infield for 15 MLB seasons. He started with the Expos, then traveled the Dodgers, Cubs, Cardinals, Royals and Indians. He was a good player. Hit .289/.332/.393 with 90 home runs in 1802 games. He made one All-Star team, had one Gold Glove. Baseball Reference has him at a 26.3 career WAR. He does have a Hall of Fame last name.
Mike Hampton pitched 16 seasons in the majors. He had one very good season, 1999, going 22 and 4 with a 2.90 ERA for the Astros, finishing 2nd in Cy Young voting (Randy Johnson won that year). He made two All-Star teams, won one Gold Glove and had 5 Silver Slugger awards (they give Silver Slugger awards to pitchers??). He was a pretty good hitter, for a pitcher, hitting .246/.294/.356 with 16 home runs in 725 at bats. He finished his career 148-115, with a 4.06 ERA, in 419 games, 355 starts. He played for the Mariners, Astros, Mets, Rockies, Braves, Astros again and Diamondbacks. Baseball Reference has him at a 20.8 career WAR.
It is Trevor Hoffman's first time on the Hall of Fame Ballot. Hoffman played 18 seasons, 16 of them with the Padres. He was closer for most of those years.
He pitched in 1035 games, no starts. Had a 2.87 ERA. In 1089.1 innings, he allowed 307 walks with 1133 strikeouts.
The big number, of course, is the 601 saves, putting him second to Mariano Rivera on the all-time list. He is also 11th in games played as a pitcher.
He made 7 All-Star teams. He got Cy Young votes 4 times, finishing 2nd twice. And he had MVP votes 5 times (yes, he received MVP votes, one year, without getting any Cy Young votes that year. I'd love to hear the explanation for that one.
Baseball Reference has him at 28.0 career WAR.
His Hall of Fame candidacy revolves all around that 601 saves. Whatever you think of the saves stat, being second all time is pretty impressive. But then, the only pitcher in the top 10 saves list to be in the Hall is Dennis Eckersley (who is 6th, but ). Two others are with him on the ballot this year. And three others aren't eligible yet. I'm pretty sure that the number one guy on the list will make the Hall.