It’s almost five years to the day that Seth Rogen last hosted “Saturday Night Live.” (Somewhat amusingly, his “Neighbors” co-star Zac Efron hosted the very next week.) Meanwhile, over the last five episodes, “SNL” itself has survived a rather rocky start to the post-Seth Meyers Era with a string of solid albeit non-classic episodes after the Jim Parsons-hosted debacle. Heading into its final break of the season, it will be interesting to see if the show ends on an upswing or downswing heading into the final stretch of this flawed yet fascinating season.

As always, I’ll be liveblogging, assigning grades to each segment. As always, those grades are designed in a lab to make the maximum number of people on the internet angry. They couldn’t possibly be an inherently imperfect way for one person to sum up his or her thoughts about a sketch comedy show in real time. Clearly, this is science. Evil science. The non-Kelly LeBrock kind. In other words: the most evil of all the evil sciences.

See you here at 11:30 pm EST when the show kicks off.

Coachella: Paul Ryan and Jeb Bush appear at the festival to introduce the “new” Republican Party. That means using words like “homeslice” and “ratchet,” because HIP! The point of the sketch is that the youth-centric crowd despises the policies being espoused onstage, but the silence in-sketch is also combined with silence in the actual crowd of the show, which seems to throw both Beck Bennett and Taran Killam off. Late appearances by Nasim Pedrad and Brooks Wheelan don’t do much to elevate the latest in a long line of tame political cold opens. The only interesting thing here? All of those first-year cast members in a cold open. That has to be a record for this year. [Grade: C-]

Monologue: Rogen decided to keep a journal of his third time hosting, and wants to share it with the audience. Highlights include: taking “writing aides,” pranking James Franco on Instagram, and being mistaken for Joe Rogan from “Fear Factor.” We also get cameos from Zooey Deschanel, Franco himself (showing up as part of a PR push to get over the aforementioned Instagram fiasco), and Taylor Swift, who steals the monologue with one line. (“Whenever a man shows emotion, that’s when I appear!") It’s a scattershot monologue, but has as much shaggy-dog charm as Rogen himself. His friends are more famous than ours, but somehow most of us don’t hate him for that. It’s a neat trick. [Grade: B]

Shallon: She’s back, this time to mess with the head of a D.A.R.E. official. Instead of saying no, Shallon’s all about smoking that crack, especially if it means she feels good after failing a spelling test. It’s the same sketch as always, but it’s one of the few instances in which the large cast gets to equally shine as they all catch Shallon Fever. It’s also one of the few remaining times for Pedrad to guarantee some face time on the show. The co-MVP of the sketch is Bobby Moynihan, especially with his exhortation for Rogen’s instructor to “put a ring on it.” Like “FOX and Friends,” “SNL” realizes it has a dependable sketch here, one that may never hit a home run but consistently hits singles and doubles. Rogen’s crisp delivery and big energy here helps makes this one a solid entry in the series. [Grade: B+]

CNN Pregnancy Test: This is a clever approach to mocking CNN’s propensity to stretch out a story without delivering actual news. It never explicitly references the recent coverage of the missing plane, but it’s there all the same. This might play differently in a few years time in which the overall context might not be as clear. Still, the commercial plays in general terms under the assumption that CNN isn’t about to change its general alert policy anytime in the near future. That’s probably a safe assumption. Bennett and Vanessa Bayer have developed some nice chemistry this season, so it’s not a surprise to see them work well together here. [Grade: B]

Dinner Party: Rogen and Aidy Bryant play a couple working through a new issue: Bryant’s character Helen has broken both arms, and Rogen’s boyfriend Alan has to do everything for her. “This has been the hardest chunk of my life so far,” he says. “And I was in Afghanistans!” (Yes, plural.) It’s an exercise in physical humor, with Alan unable to put on her lipstick and interpreting “cut it” to mean “fart” rather than “chop up her steak into bite-sized pieces.” It’s all horrendously immature, but it’s also really funny to watch Bryant and Rogen avoid eye contact lest they break after the fart sound effect. I’m not sure the sketch needed the other three players around, as Bryant/Rogen working through their issues in a public place might have made for a leaner, funnier segment. Still, there was more good than bad here, and is the type of fun, if unmemorable, sketches that we’ve seen a lot of in the past four episodes. [Grade: B]

Monster Pals: The post-Lonely Island world of digital shorts really started with “Sad Mouse,” a melancholy yet ultimately hopeful exploration of connection. It was like nothing the show had done in quite some time, and signaled a space in which the show could explore old types of storytelling in this new-ish format. “Monster Pals” is the spiritual sequel to “Sad Mouse,” with a heartfelt story wrapped in bizarre packaging. There’s no way a grunting monster’s search for his newly-assimilated friend should be so moving. Yet, I felt SO BAD for the monster when he appeared on  TODAY reaching out via a hand-made sign. This is the best digital short since “Blockbuster,” and fits in well with the adventurous nature of the best digital shorts since Andy Samberg’s departure.  [Grade: A]

Blue River Dog Food: On the one hand, this is a simple but effective escalation of rage. No frills, just great writing and equally great onstage execution. On the other hand: CUTE PUPPY. On the other hand, let’s talk about the fact that Rogen has great chemistry with every female member of the cast. On the other hand: HOW CAN I OWN THAT PUPPY? On the other hand, let’s remember Cecily Strong is probably the future of this show, and this was her best sketch since dueting with Jimmy Fallon in the Christmas episode on "Baby, It's Cold Outside." On the final hand: I SAW THAT PUPPY FIRST AND NONE OF YOU CAN HAVE HIM OR HER I DON’T KNOW WHAT GENDER THAT DOG WAS BUT I WANTS IT. [Grade: A-]

Ed Sheeran takes the stage to perform “Sing”. It’s just him, a guitar, and an initially spare stage that eventually gives way to full lighting and a full band. The song has a nice Bee Gees’ vibe, but that being said, I prefer a less urgent brand of Sheeran. This man alone with an acoustic guitar can actually produce more dynamics (and more emotion) than a full band. And while having them is probably an inevitability for his career (ie, he can’t and doesn't play solo acoustic shows all the time), this is an instance of more being slightly less. It’s not bad, it’s just not Sheeran’s finest. [Grade: B-]

Weekend Update: David Ortiz (Kenan Thompson) appears to defend his Samsung selfie with President Obama, prompting the Red Sox slugger to make an impromptu pitch for the company’s products. (“Samsung Galaxy: If it can’t fit into MY pants, that’s a problem.”) That leads to other slogans he’s coined in other commercials, including, “Do you suffer from depression? Don’t!” Afterwards…is that Jacob The Bar Mitzvah Boy? We really are moving on from Seth Meyers, aren’t we? HOW DARE YOU, “SNL”??? I kid, of course. After weeks of awkward growing pains, both Colin Jost and Cecily Strong attempt real interaction with their interviewees this week. While not perfect, at least it exhibits them feeling their way towards something approaching “comfort” behind the desk. Also…I feel like I have to bump this grade up at least half a point for Vanessa Bayer’s technique for wiping away Derek Jeter-inspired tears. That was amazing. [Grade: B+]

Wedding Rehearsal Dinner: Well, here’s a good way to ruin the great vibe this show has had exhibited so far. Strong plays the obnoxious cousin to Rogen’s recently engaged man, and takes this opportunity to tell the entire party about the one time Rogen’s character engaged in oral sex with another man…who was asleep at the time. It’s a wholly unpleasant sketch, not because of the subject matter but due to the nature of Strong’s character. It also feels severely unrehearsed, which is odd due to the overall efficient staging of everything else so far. Oh well. They all can’t be good. [Grade: C-]

Undercover Sharpton: Great idea, poor execution. Not really much more to say. I’m trying to remember the last time a crowd was this silent for a sketch. I remember plenty of times in recent memory where I’ve heard that nervous, I-am-laughing-because-this-is-so-awkward-and-this-is-my-defense-mechanism brand of laughter sprinkled through a segment. But this was straight up stony silence. Those onstage gave it their all, but the audience did not care one bit. I don’t think this was particularly awful. It wasn’t good, but didn’t merit the muted reaction, either. [Grade: C]

Ed Sheeran returns to perform “Don’t.” Jason Mraz is tuning in right now and wondering if he’s having an out-of-body experience. Still, this laid-back vibe suits Sheeran better, with the rhythm section less insistent and more supportive of his simple guitar line. (The bass line musically twins it.) Throw in a soaring chorus, and you have one smooth, catchy pop song. [Grade: B+]

A Very Smokey 420 Time: If it’s 12:50 am, it must be Kyle Mooney time! New theory: The audience themselves left for pizza after “Update,” and that’s why it’s been so quiet over the last half hour. Or maybe the quality of the sketches just fell off a cliff. More likely. I enjoyed Mooney’s short last week (“Flirty”), but this was a step back into the type of mumblecore stuff that is simply overplayed at this point. [Grade: C-]

Herman And Sons Sperm Bank: While an improvement over anything else in the post-“Update” world, this episode-ending sketch wasn’t anything particularly great. The audience is so sleepy at this point that it takes them way too long to catch up to the sperm/yogurt crossover disaster potential. But on top of that, the history of this company (started before artificial insemination was even a medical procedure) is pretty amusing. With nothing more to analyze here, it's an appropriate time to say Seth Rogen has been as game a host as you could possibly want, especially during the more dire sketches. Even if certain cast members seemed to already be on vacation, Rogen tried to hold this last half hour together himself through sheer force of will. [Grade: B-]

Best Sketch: Monster Pals

Worst Sketch: “A Very Smoky 420 Time”. I didn’t like “Wedding Rehearsal Dinner,” but that’s a bad execution of a potentially interesting idea. But the Mooney shorts have hit a rut, and they are less than a year old in terms of “SNL” time. That’s not good.

Biggest Theme: A tale of two halves. Much like the Kerry Washington episode, this episode featured a pretty killer line-up pre-“Update” and then ran out of gas. I’d still rank this as a pretty good episode as a whole, but upon rewatch, I’d just stop after Jacob The Bar Mitvah Boy leaves.

The Silent Theme: C'mon, live crowd: There was some less-than-stellar material here tonight, but the cold shoulder you gave the episode seems somewhat undeserved.

Next Time: Andrew Garfield hosts the show when it returns May 3.

What did you think of tonight’s show? Do you agree that the second half bore little resemblance to the quality of the first half?