Greatest closer ever? Sure - bearing in mind that the position didn't exist before about 1979. Rich Gossage wasn't a closer. He was a relief ace.

Easily the best ever. Because closers tend to be in the 60-80 IP range, you tend to see quite a bit of statistical fluctuation: groove a pitch for a three-run homer and your seasonal ERA just jumped by 40 points...a week of dead-arm and it doubles.

But because Rivera minimizes the longball to such an extent (he's the active leader in HR/9 at 0.50, or roughly a home run every 15-18 save attempts), there is almost no variation in his numbers; it's not just that he has been the best closer in baseball from 1997-2006 and perhaps beyond, it's that he was the best closer in each and every one of those seasons, subjectively and statistically. For 10 years, his ERA+ didn't drop below 160, and even now at 39 he is holding it above 140. And that's exactly what you want in a closer; a guy who is nearly impossible to hit and isn't susceptible to big innings is vastly superior to a flamethrower who can be turned around for a game-changing blast.

As a final note about his overall dominance, Rivera currently leads the all-time ERA+ board...by 43 points. The guy who would be second, if he had enough innings? That'd be Tom Henke, a couple points clear of Pedro.

(And not only was that Rivera's first RBI, it's the first time in his major-league career that he has reached base safely, bumping his combined regular and post-season OBP to .100)

I hate to say it, but yeah.

What's even more unbelievable is, he did it all with just one pitch. Mind-boggling i the only word to describe it.

He likely is... although I'm not sure why pitching in New York makes it any more impressive besides the hype factor.  Hoffman has had a sparkling career and spent more time in San Diego than Rivera has in NY, I wouldn't discount him because of a couple of short stints elsewhere to start and end his career.

If Rivera isn't the best ever closer, who is? He's clearly superior to Hoffman, mostly due to otherworldly HR prevention. Hoffman is probably the second best closer of all time, while "best reliever" puts Wilhelm in the conversation.  Asking if Rivera is the best closer of all time is sort of like asking if Piazza is the best hitting catcher of all time, or Schmidt is the best 3B of all time - no disrespect to the other guys, but it's pretty clear. Not many "positions" where there is a more clear-cut answer.

 

If you're looking at the modern era for cloers, i think Wagner's the only other guy you can consider, although I woudn't put him with Mo.  The problem is that the modern era for closers is so short.   Yeah, Mo has the best ERA+ for a pitcher with more than 1000 innings, but lower that threshold a bit and Tom Henke is right behind him.  Way fewer saves though, for usage and career length reasons.

Rivera has done it in the post-season

And how! 117 innings against playoff teams with an ERA of 0.77. That's insane.

Rivera and Hoffman are two of the most dominate closers ever, hands down.

 

One guy that is major league overlooked in my opinion though is Lee Smith.  I would put him in the upper echelon of closers as well.

Joe Nathan gets my vote for most underrated. He got a late start as a closer, at age 29. Since then, he's put up sub-two ERAs every year but one, and his peripherals that year were in line with his norms as a closer.

Hard to reconcile his closing career with his age 25 season, where, as a failed starter, he walked more than he struck out. Of course, Rivera started his career as a failed starter as well.

One guy that is major league overlooked in my opinion though is Lee Smith.  I would put him in the upper echelon of closers as well.

Hear, hear! That's why I mentioned him with Eck in the lede above. Absolutely a HOF guy and it's a disgrace he was not so honored.

Lots of good closers over the years, but what does it take to be a HOF'er or the #1 at the position?

1. Lots of saves - under 300 and you don't get in unless you are Hoyt Wilhelm.  Must be at or near the all-time record when you retire as well - Wilhelm had the record from 1964-1979, then Rollie Fingers from 1980-1991 at 341, then briefly Jeff Reardon held it before Lee Smith held it from 1993 to 2005 (478) and Trevor Hoffman took over to today.
   
2. Led the league in saves often
3. Won awards (Cy Young and ideally MVP)
4. Struck out a lot
5. Had a story

HOF'ers are...
Hoyt Wilhelm - knuckleballer who hit a home run his first AB then never hit another one, 2 ERA titles (one as a starter, one as a rookie reliever), effective his one time in the playoffs, 5 time all-star (plus 3 extra appearances back when they played 2 all-star games), 4 times getting MVP votes, oldest player in his league his last 8 seasons (!)  A very unique talent.
Rollie Fingers - a name that sounds cool, all-time leader in saves for a long time, 7 all star games, 7 times got MVP votes (1 win), 4 times on the Cy Young ballot with one win.  Only led in saves 3 times.  Just 3 times over 140 for ERA+ over 17 seasons though.  Cool moustashe.
Dennis Eckersley - sidearmer who seems to do great at the right time except for 2 very memorable situations (Gibson's HR and Alomar's).  Some success as a starter but was super-lights out for about 5 years.  6 times over 140 for ERA+ but just 4 times as a closer surprisingly enough.  Led in saves just twice.  5 times on MVP ballot with 1 win, 6 times on Cy Young ballot with one win.  Really a lot weaker case that I recalled.
Bruce Sutter - Viewed as a HOF mistake by many, known for 'creating' the split fingered fastball.  5 times led in saves during a short 12 year career, 6 ASG, 6 times on the MVP ballot, 5 times on Cy Young (1 win), top 10 in saves all but 3 seasons (rookie and last 2 injury filled ones).  5 times with ERA+ of 140+, twice over 200 (over 100+ IP both times).  Better case than I thought.
Rich Gossage - Cool look, nick name (Goose), great years in NY, would've been in a lot quicker if he retired after 1988 rather than playing extra 5 years with just 8 saves in middle relief role.  Led in saves just 3 times, 9 times with a 140+ ERA+ peaking with 3 over 200.  9 ASG, 5 times on MVP ballot, 5 times on Cy Young.  Even a better case than I recalled, no idea what those *(#&! writers were thinking keeping him out so long.

It is interesting going over the guys the writers put in.   For comparison...
Trevor Hoffman - led in saves just twice, 10 times with a 140+ ERA+, twice over 200 (one was just 22 IP, another high ERA+ was over 9 IP).  Never below 100 for ERA+.  6 ASG, 5 MVP ballots, 4 Cy Young. 
Lee Smith - 4 times led in saves, 5 times over 140 for ERA+, just under 100 once (final season), 7 ASG, 4 MVP ballots, 4 Cy Young ballots (no wins).
John Franco - the other guy over 400 saves (could win a lot of trivia contests with that one), 3 times led in saves, 12 times over 140 for ERA+ with 3 200's.  Sucked his last 2 years though.  4 ASG, 2 MVP ballots, 1 Cy Young ballot
Tom Henke - local favorite, ended on a high note with 36 saves and a 230 ERA+ but just didn't feel like playing anymore.  8 times with 40+ IP and a 140+ ERA+ with 2 over 200.  Just once below 118 for ERA+ while a rookie in Texas.  Led in saves just once, 2 ASG, 3 MVP ballots, never got a Cy Young vote.
Mariano Rivera - best for last.  3 times leading in saves,  9 ASG's (so far), 8 times on MVP ballot, 5 times Cy Young votes, 76 playoff games with 34 saves and that crazy 0.77 ERA.  The only man with 50+ saves twice.

Now, in case you were wondering about my 140 standard for ERA+... Rivera has had an ERA+ BELOW 140 just once, his rookie season when he was a starting pitcher.  9 times over 200 (60+ IP each time).

This isn't a battle, this is a slaughter.  Rivera is just so far beyond the pack it is silly.

It's very, very hard to get a handle on Eckersley, of course. His career was most unusual and there's a great deal of noise in the data. His insane 1990 season must be the best season by any closer, ever. But he didn't even become a closer until he was 33 years old and had started more major league games than Lefty Grove, Sandy Koufax and a bunch of other Hall of Fame starters (Bob Lemon, Dazzy Vance, Rube Waddell, Mordecai Brown, Chief Bender). One wonders how he would have done if he'd come up as a closer - but he was an outstanding major league starter when he was 20 years old so it obviously never occurred to anyone to find out.

Anyway, with his late start, Eckersley had just a five year run as an elite closer and another five years after that as a pretty ordinary one (he pitched until he was 43.)  Half his career - ages 20 through 31 - was as a starter. He spent one year as a swingman, ten as a closer, and finished up with one more as a Guy in the Pen. Three quarters of his career innings are as a starter, and almost half of his career relief innings come after he turned 38 and was well, well past his prime.

The obvious differences between Eck and the Sandman? Eck had even better control than Rivera, but a pretty significant platoon split - anyone who actually remembers Eckersley will recall that funky high sidearm delivery that came from somewhere out of left field. Right handed batters were pretty well helpless from the day he arrived in the majors. His career numbers against RH batters are basically identical to Rivera's: .214/.255/.338 for Eckerlsey, .219/.275/.328 for Rivera. That's utterly phenomenal - remember the great majority of those at bats against Eckersley  were accumulated during his long career as a starter.

But LH batters always had a shot against him, while Rivera actually has a reverse platoon split - he's tougher on LH batters. Rivera has been even tougher on LH batters than Billy Wagner (who essentially has no platoon split at all.) And while Wagner is harder to actually hit than either Rivera or Eckerlsey, his control is merely good (as opposed to Rivera's exceptionally good and Eckerlsey's near-perfect control) and like Eckerlsey he's considerably more vulnerable to the long ball than Rivera.

Rivera is easily the best reliever ever, in my opinion.   He is among the top 25 pitchers also. 

His insane 1990 season must be the best season by any closer, ever.

Agreed -- though I do think Gagne's 2003 is darn close. Now contrast Eckersley's season to Rivera's career post-season numbers.

Eckersley, 1990: 73 IP, 1.2 IP/G, 5.1 H/9, 0.5 BB/9, 9.0 SO/0, 0.5 HR/9
Rivera, PS: 117 IP, 1.5 IP/G, 5.5 H/9, 1.2 BB/9, 7.1 K/9, 0.3 HR/9

Rivera loses out on BB/9 and SO/9 and slightly on H/9, but wins on IP/G and HR/9, and deserves some form of mathematical adjustment to address the strength of competition.

Using the Bill James technique of subtracting one line from another, here is Rivera's line minus Eckersley's line:

44 IP, 31 H, 2 R, 5 ER, 12 BB, 20 K, 1.02 ERA, 0.41 RA (4 of Eck's 9 runs allowed in 1990 were unearned).

 

Yup, best ever by a long-shot. It's the most overrated position in baseball though. I mean, Roy Halladay has already thrown almost twice the IP as Rivera as a starter and nobody would consider him a HOFer yet. Don't get me wrong though. Rivera deserves to be in, but the position has become absurdly overrated.

Notes from the ballpark. Bautista in RF, Adams in LF. Alex Rios gets to sit and watch.

Well, I guess I can't complain about a passive-aggressive response.  Rios is officially in the doghouse.  Oh well. Rios has been a good player over the last 2 and 1/2 years, while Wells has not been, but this doesn't seem to matter.

Rios has been a good player over the last 2 and 1/2 years

Are you counting this year because he's been pretty atrocious.

 

Today's bench sorted by Batting average:

J. McDonald .269
R. Chavez  .269
A. Rios  .263
K. Millar  .243

Rios has been a good player over the last 2 and 1/2 years, while Wells has not been

How was Wells not a good player in 2008? He wasn't the healthiest guy, but he was a damn sight better than Rios last year.

I was speaking cumulatively, Magpie.  Wells has basically hit the way  Joe Carter did after he turned 35, and while he does play centerfield, he doesn't have the range that he had 5 years ago.   He would probably be a good defensive corner outfielder.  That does not mean that Wells cannot return to his career batting norms over the next few years.  As a corner outfielder hitting .290/.340/.475, Wells would still be a good player. 

Who still uses batting average? Scottt, you must go to www.fangraphs.com now.