Jacob deGrom looked a lot like Pedro Martinez on Friday

On Friday night, we witnessed a matchup of starting pitchers in the Dodgers vs. Mets series that only comes along a few times every generation. Clayton Kershaw -- in the middle of a career that is already alongside some of the great starting pitchers in history -- went head-to-head against Jacob deGrom, a leading National League Cy Young Award candidate and ace of the Mets staff.

Perhaps we shouldn't have been surprised about the combined numbers the two starters produced: 13.2 IP, 9 H, 5 BB, 3 ER (two of which scored after Kershaw was replaced), and a staggering 24 strikeouts. The tally of strikeouts, for those who weren't watching, was historic: Friday night marked the first game in postseason history that two starters each had at least 11 strikeouts. And, while Kershaw was very good, deGrom was better, going a full seven innings while allowing only six base runners, no runs, and 13 Ks. "Better" is in fact a serious understatement, as deGrom scythed through one of the best offenses in baseball in what was one of the most dominant postseason debuts in recent history.

Earlier this season, when Pedro Martinez was about to be inducted into the Hall of Fame, I wondered: what current starting pitcher possesses the same arsenal of pitches (by velocity) as vintage Pedro? While many commenters simply wrote "no one" in response to the article (an understandable response, given Martinez's dominance), the answer was actually deGrom: possessing a fastball, changeup, and curveball that clocked in at almost identical speeds to 1999 Martinez.

We don’t have any data on how Martinez's pitches moved, so comparing the all-important "nastiness" factor between Pedro and deGrom is impossible. However, the conclusion is there: deGrom has the stuff to compare to Martinez, and that simple fact is remarkable. This section toward the end of that piece comparing the two pitchers sums up both the limitations and excitement of the exercise:

Jacob deGrom isn't Pedro Martinez. Basically no one can make that claim, and deGrom has a long, long way to go before their careers can be compared. However, for a few brief hours on Friday night, deGrom was almost as dominant as peak Martinez, and he was dominant in very similar ways. The similarities between the two were already there, and in many ways, they were cemented in the first game of the NLDS. Let's dive into deGrom's start to explain further.

First, there was the electric fastball, which compares very well to Pedro's. Sitting at an average of 97 mph, he quickly established the pitch on Friday, throwing 85 percent fastballs in the first inning alone. From then on, he relied on the fastball in all situations and counts as his main pitch, only deviating from that plan to mix in first-pitch sliders to 44 percent of the right-handed hitters he faced. In fact, most of the "trouble" he got into on Friday night was against righties, so he pitched backwards to those hitters later in the game, relying on offspeed pitches early in counts to keep them off-balance.

In the first few innings, he relentlessly went after righties early in the count with fastballs before getting weak contact or whiffs with sliders, as he did to A.J. Ellis in the second inning:

The second time through the lineup, he started pitched backwards to the righties, starting off with sliders before hitting his corners with fastballs, like this Howie Kendrick at-bat in the fifth:

The story was very different against left-handed hitters, and it's where the comparison to Martinez really starts to become clear. However, before we get to how deGrom approached lefties, we should quickly talk about the weapon Pedro was famous for: his changeup. For Martinez, the pitch neutralized almost all of the natural platoon advantages left-handed hitters had against him, which is one of the reasons why his career splits for lefties and righties are almost even in terms of opposing offensive production. At its best, his changeup looked like this:

A hard changeup with tons of fade from a right-handed pitcher can be incredibly effective against lefties, which is why many starting pitchers (such as Felix Hernandez) base their careers off the pitch. deGrom is no different; his changeup grip is very similar to Martinez's, is thrown at the exact same speed that Pedro threw his, and it has steadily gotten better over the past two seasons. In 2014, his changeup generated 19.6 percent whiffs; this season, that rate improved to 23.8 percent.

On Friday, his changeup was perhaps the best it has ever been. Four of his 13 strikeouts came on the pitch -- the most of any offering besides his fastball -- and it possessed the most vertical movement out of any of his starts this year. Take a look at how much vertical drop his changeup had per start over the course of the season, courtesy of Brooks Baseball (Friday's start is highlighted by the red arrow):

With the comparison to Pedro established, it shouldn't be a surprise that deGrom's changeup was a main driver of his success against left-handed hitters on Friday. In the beginning of the game, he flashed it early in counts as a way of changing speeds; later in the game, he used it as a strikeout pitch. deGrom's final two strikeouts were both on changeups, and he showed the type of sequencing and movement during his final out that makes it such an unhittable pitch. Against Chase Utley in the bottom of the seventh, notice how he goes high and inside with his fastball (pitch 4) on a 1-2 count to set up the changeup down and away (pitch 5):

After seeing a 97 mph fastball in on the hands, an 87 mph changeup down and away is basically unhittable if you're a lefty: it looks like a fastball on the outside part of the strike zone, but then the bottom drops out of it. It's what made Pedro so effective at getting lefties out, and it was a big part of what made deGrom so effective on Friday night. In total, deGrom held lefties to a staggering 1-17 with 12 strikeouts in Game 1 of the NLDS: considering five out of nine of the Dodgers' starting lineup batted from that side of the plate, their inability to score runs makes a lot of sense.

We talk a lot about stuff in baseball because it's impossible to miss. Jacob deGrom has always had stuff, and we knew that -- we even saw earlier in the season that he shared a lot of similarities with the 1999 version of Pedro Martinez. What we don't talk about often is game management and pitch sequencing, because they're harder to notice, buried a level or two down below the surface of the game.

Earlier this year, we said that deGrom probably didn't yet have the intangible skills that Pedro had at his peak. Maybe he didn't know hitters well enough; maybe he didn’t have the sequencing or management area of dominant pitching figured out yet. If what we saw on Friday night is any indication, however, that could be changing -- and quickly.