The 2018 Red Sox have already had their fair share. I tried to do my best to nail down the ones that have been the most vital to their hot start, and the most surprising.

Rick Porcello keeping the ball in the yard

Porcello gave up a league-high 38 home runs in 2017, resulting in a ghastly 1.7 dingers per nine innings. It was a career high, and one of the driving factors behind his 4.65 ERA.

This season has been the opposite. No, like the total opposite. He hasn’t even given up a single home run yet in 25.2 innings pitched.

And he’s had plenty of chances. He’s faced the New York Yankees, a squad which boasts the vaunted Giancarlo Stanton-Aaron Judge-Gary Sanchez power trio. He held them to a pair of hits over seven scoreless innings. Then came the Angels, who lead the American League with 26 dingers.

He and Chris Sale have combined to create the league’s most dominant one-two punch thus far. As I wrote last week, Porcello’s success is the team’s X-factor. Him laying off the home run balls and piling on the strikeouts certainly helps.

Mitch Moreland thriving in limbo

When the Red Sox added J.D. Martinez, everything improved… aside from Mitch Moreland’s clarity towards his role for 2018 and beyond.

Mitch Moreland was more than serviceable as the team’s starting first baseman last season. With Martinez in the fold, a bit of a logjam has been created at the position. Martinez moved Hanley Ramirez mostly back to first, as he has rotated between designated hitter and outfield.

That leaves Moreland, who’s been in proverbial limbo, bouncing from the bench to the starting nine, and from first base to designated hitter.

If you want to put it into basketball terms, he’s the sixth-man. A late game defensive substitution at first. A starter when Martinez is in the outfield and Ramirez is DH’ing. He’s all over the place, and he’s been killing it.

He’s hitting .343 in his new role, with an OPS of 0.986. Against the Angels on Wednesday, he went 3-for-4 with a home run, a walk and three RBI.

If this Boston team has real World Series aspirations, depth will be key. If Mitch Moreland can keep contributing like he has (although hitting .355 for the rest of the season might be a tad lofty) the depth will be alright.

The team’s 5-1 record against New York and Los Angeles

Was anyone exactly surprised when the Red Sox opened the season 8-1 against the rebuilding Tampa Bay Rays and Miami Marlins? Not exactly. Anything less might have been a disappointment.

But to follow that up with a 5-1 record against one team expected to win its division by many pundits (New York) and another team leading the AL West (Los Angeles) all while mixing in a sweep of the Orioles? That’s a real resume booster.

The Sox have done it in a number of ways. With pitching, with hitting. In blowouts and it close wins. This, more than anything, is optimistic to see as we begin to reach the point of the season where its decided whether teams are “for real” or not.

Header photo by Richard Mackson — USA TODAY Sports

Yep, it’s out there now. So when he allows five runs in three innings in his next start, you know who to come blame — me. But for a minute, let’s just imagine a world where Porcello maintains the pace he’s at now and doesn’t turn into a pumpkin.

This Red Sox rotation will be incredibly dangerous.

On paper, that’s no surprise. But we know that things don’t always happen as they do on paper. This staff features a pair of former Cy Young award winners (and Chris Sale, who is still the best of the trio).

Sale is a model of consistency. His career ERA is 2.96, and in his “worst” season, he had a 3.41 ERA. He, out of anybody on the roster, is probably the safest pick to repeat their 2017 performance.

Price is trending up (or at least he was prior to leaving Wednesday’s start with an arm injury.) His 3.38 ERA 2017 season in which he struck out 76 in 74.2 innings has transitioned nicely into a promising 2018. Injuries might be the wild card with Price, but he has the history of being elite on his side and in his favor.

And then, there’s Porcello.

He’s been practically unhittable and he’s shown some of the best control of his career. He hasn’t allowed a ball to leave the yard yet, and his ERA and FIP are objectively beautiful.

He’s had a fascinating last few years, really. After coming to Boston, he’s sandwiched a Cy Young-winning season in between a pair of high-4 ERA years. If you believe in patterns, he’s due for another strong season.

If you choose to buy into numbers as opposed to semi-arbitrary patterns, he has those working for him, too. He’s been practically unhittable (14 hits allowed in 19.2 innings) and he’s shown some of the best control of his career (17 strikeouts to a single walk). He hasn’t allowed a ball to leave the yard yet, and his ERA (1.83) and FIP (1.61) are objectively beautiful. He’s throwing lots of sliders and changeups, about as much as he had for the entirety of his career. He just shut down a struggling, albeit dangerous Yankees lineup.

Of course, it’s early. As far as I’m concerned, it’s still going to be “early” until about May. But Porcello is currently passing the eye test.

So where does that leave the Red Sox? It leaves them with at least a dominant three-headed dragon of a rotation. The back end still has some question marks, headlined by roughly 17 pitchers who could fill the back two spots (maybe not that many, but it sure feels like it).

There’s still plenty of time for Porcello to look like his 2017 self as opposed to his 2016 self. But he might be the X-factor in this team, the one that decides if Boston will boast a good rotation, or a deadly one.

Header photo by Brian Fluharty — USA TODAY Sports

This is all a long and drawn out way to say that we’re going to be talking about a relief pitcher, one who’s been prone to doing both of the acts described above: Joe Kelly.

We’ve become accustomed to seeing two different Joe Kellys. Most recently, we’ve seen 2017 Kelly, the one with the 2.79 ERA, an 8.1 K/9 and a career-high average fastball velocity of 99.2 miles per hour. This, for lack of a better term, is Effective Joe Kelly.

But the year prior to that — his first season mostly as a reliever, it was a different Kelly. He had a career high 5.18 ERA, home runs per nine (1.1) and walks per nine (5.4). His fastball average? 97.3. This (bear with me on this one) was Ineffective Joe Kelly.

So that raises the question: which Joe Kelly is Boston going to trot out of its pen?

It’s still far too early to make any concrete judgement’s on Kelly’s 2018 season based upon his first three outings. But, if it so behooves you, the counting numbers haven’t been astounding. He’s posted a 10.80 ERA in 3.1 innings pitched on four earned runs. Of course, all four of those came in the Opening Day meltdown against the Rays, when he recorded just a single out, allowed a hit and walked three.

He’s coming off of a season in which he posted his best year as a reliever, and a big part of that was due to his dominant fastball. Kelly was running it up at 99.2 miles per hour, and it was his clear-cut, go-to pitch — he used it 64.1 percent of the time, the highest usage percentage of any pitch in his pro career.

The usage percentage of his pitches could be a better area to hone in on. The last time Kelly threw less than 50 percent of his pitches for fastballs was in 2015.

Through just 3.1 innings this season, both his velocity (97.6 mph) and usage rate (28.3 percent) are down from last season. The velocity is less of a question. It’s likely to rise as the season changes and Kelly’s arm stretches out more. On the off chance it doesn’t, settling somewhere in the mid-97s will still mirror his 2015-16 campaigns.

To me, the usage percentage of his pitches could be a better area to hone in on. The last time Kelly threw less than 50 percent of his pitches for fastballs was in 2015 — back when he started 25 games. The highest percentage of fastballs he threw as a starter was 18 percent in 2012, with St. Louis. But starting and relieving are two different things. If Kelly is tasked with getting just three batters out as opposed to an entire lineup, he can rely heavier on his heat, as he’s done the previous two seasons.

His off-speed pitches remain relatively similar to what they’ve always been. His career average percentage for his slider is 11.9 percent, although it might be higher if you take away an outlier 2014 season in which he threw it just 5.7 percent of the time. So far in 2018, he’s tossed his slider 17.9 percent of the time. His sinker percentage is up — more than his true fastball, actually (42.5 percent to 28.3 percent). His velocity on the pitch is the highest in his career, too (98.2, which is up from his career average of 95.6). The last time he was chucking this many sinkers was back when he was a starter.

So, what does this all mean? It means Kelly (historically) is most effective out of the bullpen when he leans on his fastball. But, early on, his sinker has been even faster, and he’s using it more than his standard fastball, something he’s shied away from doing since he was a starter.

It’s still too early to tell if these numbers are just outliers. This time next month, they might revert back to their 2017 numbers. Or maybe they don’t, and we see a version of Joe Kelly out of the bullpen that’s a mix of his 2017 self and his 2012-13 self, when he posted back-to-back sub-3.53 ERA seasons as a starter.

Photo by Kim Klement — USA TODAY Sports