Mariano Rivera sits down with SVP to describe the feeling of finding out he was the first player unanimously elected to the Baseball Hall of Fame. (0:41)

Mariano Rivera became the first player in history unanimously elected* to the Hall of Fame, and he is as good a player as anybody to be that guy.

So too would have been Ken Griffey Jr., or Randy Johnson, or Joe Morgan, or Carl Hubbell.

Rivera's unanimous selection tells us as much about the changing electorate -- purged as it was a few years ago of non-working writers and now far more transparent, and arguably far more accountable, than in the past, thanks to BBWAA changes and Twitter swarms and Ryan Thibodaux's ballot-tracking project -- as about Rivera's greatness. But Rivera is undeniably great. He's a no-brainer. There's really no argument against him being in the Hall of Fame, obviously, this being an article about a guy who was just unanimously elected to the Hall of Fame.

More important, though, are two things this new broken barrier will mean for the Hall of Fame going forward. Rivera's unanimous selection has made the Hall of Fame better in two ways, and Rivera is as good a player as anybody to stand in for those two things.

Cooperstown is a better place now that Yankees closer Mariano Rivera got 100 percent of the BBWAA vote. David Handschuh/NY Daily News Archive via Getty Images

The First Thing: We have finally erased the notion that a player must somehow be perfect to merit an ultimate honor.

Along the way from 1936 to here, at least a handful of writers have found something wrong with every player who has ever played: He wasn't nice enough to reporters, or he didn't play defense hard enough, or he played in the wrong era, or -- probably, in some cases -- his skin was the wrong color. Most often, though, it appears that after a certain point, every player's flaw was being not as good as Babe Ruth (who was elected, though not unanimously, in the inaugural class) or Willie Mays (who got nearly 95 percent four decades later). From that point on, it was enough for a writer to argue that a player couldn't possibly merit unanimity, on account of his being inarguably worse than Ruth and Mays.

This has always been obnoxious -- a petty veto power a tiny minority of the voters have chosen to wield -- but it also cuts directly against one of baseball's main themes: It's a game of failure. You fail seven out of 10 times and make the Hall of Fame, they say. But here the Hall's gatekeepers had decided that in fact failure was prohibitive. No matter how good you got, you had to be perfect or else not worthy of some recognition these vetoers denied you.

Mariano Rivera does not have the most ironclad Hall of Fame case. It's pretty darned ironclad, obviously, but if a voter had wanted to get to "no," there were fig leaves one could wear:

Rivera was a reliever, which is almost always code for "failed starter." Rivera had an ERA of nearly 6 as a starting pitcher. It was just 10 starts and he was just a rookie, to be sure, but he was a fairly old rookie in part because he hadn't been a great starting pitching prospect. (In fact, he was never on a top-100-prospects list, arguably the greatest player in the prospect-rankings era to be so overlooked.) There's nothing wrong with being a failed something -- most hitters were failed shortstops somewhere along the way -- but out of 500 voters, one or two might have held it against Rivera and argued relievers are just glorified bench players.

Rivera did play in the PED era. A lot of those years! There have been voters who have said they wouldn't vote for anybody in that era because they could never know for sure who was clean.

His WAR was really low for a typical Hall of Famer. That's not a very good argument, for a lot of reasons having to do with strategy and resource management -- and his WAR was outrageous for a reliever -- but he had a lower WAR than Jim Edmonds, who was kicked off the ballot after one year.

He was the greatest postseason pitcher ever -- his legacy is built around that -- but he also authored one of the most destructive blown saves in history, to the Diamondbacks in 2001. He technically gave up the third-biggest hit in baseball history, by championship win probability added. That's also a terrible argument, but there have always been terrible arguments made about inner-circle Hall of Famers to keep them from feeling too good about themselves.

He wasn't Babe Ruth.

He also wasn't Willie Mays. Mays wasn't unanimous.

He wasn't the perfect ballplayer. And yet, his career was perfect, in its own awe-inspiring, tell-your-grandkids-about-it way, just like Ken Griffey Jr.'s was, and Randy Johnson's, and Joe Morgan's, and Carl Hubbell's. Finally, voters said this form of perfection -- the imperfect kind -- is enough for them and allowed that no honor need be withheld.

The Second Thing: We have finally killed (or, at least, are in the process of killing) the hierarchical distinctions between Hall of Famers.

The great historian John Thorn once told me, in a conversation about WAR, that the point of baseball isn't to say whether Dwight Evans or Harry Hooper was better. "The current lowest common denominator of statistical writing is the fixation on comparing Player A with Player B, which seems to me not only worthless but serves to obscure the larger story of baseball," he said.

So, too, did this concept of "unanimous Hall of Famer" obscure the larger story of Cooperstown. Everybody in it is great. There are no perfect ties in nature, so some were clearly better than others. But the point of putting one Hall of Famer in is very much not to immediately inform him he's worse than Babe Ruth. It's to tell him he's better than almost everybody else who ever tried.

I am guilty, too, of using terms like "inner circle," and we probably all distinguish between a first-ballot inductee and a 10th-ballot, or a player inducted by writers and one inducted by a veteran's committee. Maybe those are sins on our part. But creating an entire threshold above Babe Ruth -- which no player deemed "short" of that career could ever merit -- was outrageous. There are enough places in this world to rank things that Cooperstown isn't needed for that. Cooperstown is needed because there aren't enough places in the world to celebrate ballplayers of generations past.

And so Mariano Rivera broke the threshold. He's the perfect player to do it: He's absolutely, unambiguously worthy of it, and yet nobody is going to confuse Mariano Rivera for the greatest player in major league history. Nobody is going to confuse this achievement for being unattainable to the next guy. Today, we make a deal out of Rivera being the first; tomorrow, we can defetishize the achievement.

The Hall of Fame got better this week. It now has four more incredible players with four fantastic biographies. More than that, it makes more sense than it used to.

*First unanimous player other than the not-very-convincing Lou Gehrig anomaly, which you can read about here.