At the heart of baseball is the pitcher-batter confrontation. And at the heart of the pitcher-batter confrontation is the fastball, the king of pitches, the one thrown more than all others, the pitch that helps set up sliders, curveballs and changeups. And at the heart of the fastball is velocity. Man, do we love velocity.

This is why this young New York Mets rotation is not only dominant but so entertaining to watch. Jacob deGrom is 27 years old, in his second year in the majors and averaged 94.9 miles per hour on his fastball in the regular season. You wonder how he generates the power from that skinny frame with no rear end. Matt Harvey is 26, in his third season after missing all of 2014 after Tommy John surgery and he's built like the old Mets ace Tom Seaver with a thick lower half; his fastball averaged 95.8 mph. Noah Syndergaard, 23, is a rookie, 6-foot-6 with long golden locks, nicknamed Thor for obvious reasons, and his average fastball velocity clocked in at 97.0 mph. Fellow rookie Steven Matz is the mere mortal in this foursome, a 24-year-old lefty with six starts in the regular season who averaged 94.3 mph with his fastball.

It's a World Series rotation for the ages: Four young starters, four flamethrowers who can all touch 97 mph. Among starters who threw at least 1,000 fastballs in 2015, Syndergaard ranked first in average velocity, Harvey ranked fourth and deGrom ranked 12th. Have we ever seen anything like this?

Let's start here, with the top 10 average fastball velocities in the postseason for rotations since 2009 (as far back as ESPN Stats & Info has data):

2015 Mets: 96.0

2013 Pirates: 95.0

2009 Rockies: 95.0

2009 Red Sox: 94.6

2015 Royals: 94.4

2010 Rays: 94.3

2011 Tigers: 94.0

2013 Cardinals: 93.9

2015 Dodgers: 93.6

2011 Rays: 93.6

Some of those averages are skewed by a limited number of games. The 2009 Rockies, for example, played just four games with pitch-tracking data and Ubaldo Jimenez started two of those. No rotation in recent history has matched the power, depth and youth of this Mets group.

As we go back into history to find other comparable World Series rotations, let's first look at some other young groups. Since all four Mets starters are 27 or younger, I checked teams where every World Series start was made by a pitcher no older than 27. Working backwards, I found 12 such teams:

2010 Giants: Tim Lincecum, Matt Cain, Jonathan Sanchez, Madison Bumgarner

2008 Rays: Scott Kazmir, James Shields, Matt Garza, Andy Sonnanstine

1992 Braves: Tom Glavine, John Smoltz, Steve Avery

1973 A's: Ken Holtzman, Vida Blue, Catfish Hunter

1972 A's: Ken Holtzman, Catfish Hunter, Blue Moon Odom, Vida Blue

1969 Mets: Tom Seaver, Jerry Koosman, Gary Gentry

1966 Orioles: Dave McNally, Jim Palmer, Wally Bunker

1956 Yankees: Whitey Ford, Don Larsen, Tom Sturdivant, Bob Turley, Johnny Kucks

The other four all happened in the 1910s -- the 1915 and 1918 Red Sox, the 1914 Braves and the 1910 A's (who used just two starters in a five-game series, 27-year-old Jack Coombs and 26-year-old Chief Bender).

If you think the Mets' rotation is young, check out the ages of the 1966 Orioles, who swept the Dodgers, including complete-game shutouts in the final three games: McNally was 23, Palmer 20 and Bunker 21. The Glavine-Smoltz-Avery trio in 1992 was 25, 21 and 24 (all three had started in the 1991 World Series as well but were joined by 34-year-old Charlie Leibrandt). The Giants' foursome in 2010 included 20-year-old Bumgarner while the other three were 26 or 27. The 1973 A's featured Holtzman and Hunter, both 27 that year, plus 23-year-old Blue, but all three already had plenty of major league experience by then.

Having a rookie in the postseason rotation certainly isn't unusual -- think back to Yordano Ventura last season, Michael Wacha in 2013, Bumgarner in 2010. Game 1 of the 2006 World Series featured rookies Anthony Reyes of the Cardinals and Justin Verlander of the Tigers and John Lackey of the Angels and Jaret Wright of the Indians who started Game 7s in 2002 and 1997. According to Elias Sports Bureau research, however, only five teams have had two rookie starters in the World Series: The 1997 Marlins (Livan Hernandez, Tony Saunders), 1982 Cardinals (Dave LaPoint, John Stuper), 1980 Phillies (Marty Bystrom, Bob Walk), 1955 Dodgers (Roger Craig, Karl Spooner) and the 1952 Dodgers (Joe Black, Billy Loes).

So while the Mets' youth across the rotation is rare, it's not necessarily unprecedented.

In comparing the power arms in these rotations, we'll have to rely on anecdotal evidence while also acknowledging that pitchers of the past didn't generally throw as hard as pitchers today. A helpful resource is "The Neyer/James Guide to Pitchers," in which Bill James lists the best fastballs of each half-decade and various descriptions of pitchers throughout major league history. Those early '70s A's, for example, had some good fastballs: Blue might have the been the hardest thrower of the early '70s outside of Nolan Ryan; Hunter had above-average fastball velocity but was more known for his terrific command; Odom relied on a hard sinker with a lot of movement; Holtzman had what was described as a sneaky fastball -- Leo Durocher, his manager with the Cubs before he was traded to the A's, criticized him for not throwing it more -- but was best known for a big, slow curveball.

So that's a pretty good group, and this Mets rotation would do well to match their careers: Hunter is a Hall of Famer, Blue won 209 games, Holtzman won 174 and they helped the A's win three straight World Series. But Blue was the only one who had a truly plus-plus fastball for his generation.

Those '66 Orioles were interesting. Palmer was in his first full season as a starter at age 20. He certainly threw hard and was known for a high fastball that would probably be called a ball today. McNally was already in his fourth season in 1966 at 23 and had a good fastball, but his best pitch was a curveball that Mickey Mantle described as one of the best in the league. Bunker won 19 games as a 19-year-old rookie in 1964 and threw a hard, sinking fastball. Bunker developed elbow tendinitis in 1965, however, and in a 1969 AP article "he admits he became a junk pitcher and grew afraid of throwing fastballs," so we can assume he wasn't throwing too hard in 1966.

The '56 Yankees had five young starters -- Turley was one of the hardest throwers in the majors, and an article that year in The Sporting News listed both Larsen and Ford as having one of the best fastballs in the league. Ford, however, isn't remembered for having a great fastball, and James doesn't list him in the top 10 in any of the half-decades. Considering he was 5-10 and 175 pounds, I can't see him matching Syndergaard in pure velocity.

Those early '90s Braves teams before Greg Maddux? Smoltz threw hard and Avery threw hard enough while Glavine threw his fastball a lot (he estimated about 70 percent of the time in those days). Glavine's fastball was effective because he could paint the corners, he didn't have elite velocity.

If there's one group of young starters here that might compare, it's the 1969 Mets. Seaver certainly had an elite fastball, and James lists him as having the fourth-best fastball from 1965-1969 (and fifth-best from 1970 to 1974). Seaver threw both a four-seamer and two-seamer and led the National League five times in strikeouts. Gentry went 13-12 with a 3.43 ERA as a 22-year-old rookie in 1969, and James lists him as having the 10th-best fastball from 1970-1974. The Neyer/James guide has a quote from teammate Ron Swoboda as saying Gentry's "stuff was every bit as good as Seaver's. ... He had such a live arm." Unfortunately, he got hurt early in his career.

Then there's Koosman, who's a little more difficult to figure out. His SABR bio includes another Swoboda quote saying "Jerry Koosman threw a 90-plus fastball." Roberto Clemente said Koosman was the only guy who threw a fastball "that never moved the same way twice." Another article compared Koosman's fastball to a cutter, running in on right-handed batters. Koosman himself said he threw a lot of fastballs, believing in pitch efficiency. You put all that together and it seems to me that Koosman must have had a good fastball. I'd compare low 90s in the late '60s/early '70s to a mid-90s fastball now. What's interesting is that Koosman apparently lost his velocity for a couple years in the early '70s but regained it and actually led the NL in K's per nine in 1977. Koosman also lasted until he was 42, a sign he had an excellent fastball when younger.

(And for good measure, the '69 Mets had a young part-time starter named Nolan Ryan working out of the bullpen that World Series.)

There are a few other World Series rotations worth mentioning, although they don't compare to these Mets in their youthfulness. The 1965-1966 Dodgers had Sandy Koufax and Don Drysdale but the third starter was finesse lefty Claude Osteen. The 1963 team that swept the Yankees started Koufax, Drysdale and Johnny Podres. James listed Drysdale and Koufax as owning the two best fastballs from 1960-1964. Podres, meanwhile, "was extraordinarily fast in 1953 ... (and) is a more rounded pitcher now, but not quite so fast" wrote the "1964 Official Baseball Almanac."

This in-depth article on the history of recorded fastball speeds shows an article on members of the 1953 Dodgers being tested for their velocity, with Joe Black hitting 93.2 mph and Podres 88.5 mph (scroll down near the end of the piece). The site uses "our groundbreaking 50 Foot Equivalent (FFE) standard" as that's apparently the distance modern fastballs are measured at in order to compare measurements of different devices through the years. I can't vouch for the accuracy of these adjustments, but in translation the site suggests Black hit 102.2 mph and Podres 97.5 by modern readings (although this wasn't in game situations, mind you).

The 1967 Cardinals rotation included Bob Gibson and Steve Carlton, who both made James' top 10 for 1965-1969, but also Nelson Briles and Dick Hughes. Briles' SABR bio says he threw "a 90-92-mph-moving fastball that features a sharp-sinking action." Hughes was a 29-year-old rookie in 1967 who went 16-6 with a 2.67 ERA and had the best hits-per-nine rate in the NL. He was a fastball/slider guy who spent years in the minors due to control issues, but in this article, Hughes estimated he threw in the mid-90s. Did Hughes really throw that hard? Hard to say. He tore his rotator cuff the next spring and only pitched a few more games, and the few stories I came across mentioned his slider more than his fastball.

Anyway, one more team to rival the Mets. The 1929-31 Philadelphia A's won three consecutive AL pennants with three of the hardest throwers of the era: Lefty Grove, George Earnshaw and Rube Walberg. James ranks them No. 1, 3 and 8 on his best fastballs from 1925-1929, with Grove and Earnshaw holding the first and fifth spots in 1930-34. The only year they started all the World Series games for the A's was 1930, so this trio has to rank up high on any list of power rotations. Hall of Famer Grove is certainly one of the hardest throwers of any era, and the Neyer/James guide has a long section on Earnshaw with many glowing contemporary quotes on both his fastball and curveball.

In 1930, Grove, Earnshaw and Walberg ranked first, third and ninth in the AL in strikeouts per nine. Earnshaw was the hero of the World Series that year, pitching 22 consecutive scoreless innings -- he started Game 5 and then came back on one day of rest and threw a shutout in the clinching Game 6. Anyway, he was only a good pitcher for a few seasons but there's no doubt he had some of the best stuff of the era.

If I had to rank World Series rotations based on fastball velocities within their own era, I'd probably go like this: 2015 Mets, 1930 A's, 1969 Mets, 1963 Dodgers, 1967 Cardinals.

But that's just a guess. And that list is different from a list of the best rotations. After all, these Mets are just beginning their careers, their reputations just developing. I do, however, think we're seeing a pretty special and unique group. As I joked on Twitter the other day: It's the new market inefficiency; just find four young, inexpensive starting pitchers who all throw 95 mph and know where it's going.