Robert Greenblatt joined the rare ranks of TV executives to go out on his own volition when he formally announced his departure from NBC on Sept. 24. His network has won four of the past five seasons, a whiplash-inducing 180-degree turn from the NBC Greenblatt inherited. And the coming season, one where he will only serve as a consultant to the new regime, is in solid shape.

Greenblatt (Bob, if you’re feeling informal) now heads into a wide-open future, one that is almost sure to include some level of theatricality. His fondness for the stage — live musicals, Smash, that famous piano accompaniment to Dolly Parton at 2016 upfronts — will be one of his enduring stamps on NBC.

There’s a lot of history between Greenblatt and NBC, but there are the ups and downs that stand out.

High: The Voice
Greenblatt inherited NBC at the start of 2011. To say it was in bad shape would be an understatement. It was the lowest-rated and least-watched network in the Big Four, a source of industry ridicule in commissaries and even on some of its own shows. The tide started to turn that spring, however, when previously-ordered singing competition The Voice premiered as the top new show of the season with a massive 5.1 rating among adults 18-49. The series would soon supplant Fox’s American Idol as the No. 1 reality show on television, anchor the schedule with nearly 100 hours of original programming each year and usher in NBC’s era of ratings dominance.

Low: That First Season
Riding high on The Voice, Greenblatt’s first primetime lineup at NBC produced … not a single series that lasted more than a few seasons. Lowlights included that odd Brian Williams primetime series and a string of unmemorable dramas, save The Playboy Club. That drama at least lives on in infamy, canceled after a mere three episodes. The guillotine hasn’t fallen so hard or so quickly since.

High: Dick and Bob Go to Chicago
A simple Chicago-set procedural was hardly the most exciting piece of NBC’s 2012-13 rollout. But while the monkey from Animal Practice dominated the fall’s promotions, it was Dick Wolf’s Chicago Fire that proved to be its most enduring and versatile hit. The series has spawned three spinoffs to date, two of them still on the air, and reaffirmed the Law & Order creator as one of TV’s most dependable producers.

Low: Smash Is a Bomb(shell)
Greenblatt brought over his glossy high-concept Broadway drama from his days at Showtime. With Steven Spielberg on board as executive producer, and a cast that included Debra Messing, Anjelica Huston and a pre-Hamilton Leslie Odom Jr., Smash was initially lauded — but positive ratings and buzz rapidly dwindled. By the time the second season premiered, Smash could barely pull an audience. Its demise was a sore spot of Greenblatt, but a stage musical version, Bombshell, remains on the table.

High: The Sound of Musicals
While Smash may have proved to be slightly misguided, one arena where Greenblatt’s theatrical leanings helped him out was in the network’s revival of live musicals for TV. The first, The Sound of Music in 2013, grossed a wild 22 million viewers once all platforms were tallied. Its success spawned a string of repeats — both good (The Wiz) and bad (Peter Pan) — and imitators from rival networks. It’s probably no coincidence that The Sound of Music also coincided with NBC’s first season as TV’s highest-rated among adults 18-49 in more than a decade. It's a feat Greenblatt’s Peacock has managed to duplicate three other seasons since, including the most recent one.

Low: The Mystery of The Mysteries of Laura
Greenblatt got the occasional ribbing for a few of his series orders, particularly those featuring friends. One particularly head-scratching example was The Mysteries of Laura, a post-Smash/pre-Will & Grace 2.0 excuse to keep pal Debra Messing on NBC. The ratings were tepid. The reviews were trash. And despite widespread mockery, it lasted two full seasons. Mysterious, indeed.

High: Jimmy Fallon!
The Tonight Show’s 2014 transition from Jay Leno to Jimmy Fallon was a masterclass. Audiences lapped up Fallon’s fresh spin on late-night talk, his viral videos and his second-hand rapport with celebrity guests. No. 1 status was quickly cemented, enduring rival CBS’ swapping in Stephen Colbert for retired David Letterman and scrubbing over sour memories of NBC’s Conan O’Brien debacle from a few years earlier. Fallon reinvigorated a stagnant genre, and he seemed invisible.

Low: Jimmy Fallon …
Few could have foreseen that one lingering effect of the 2016 presidential election would be audiences turning their backs on Fallon. That hair tussle, the soft monologues and the fact that all of his competition leaned hard on criticism of the Trump presidency all made Fallon an outcast in the arena he once owned. Time slot rival Colbert has been the most-watched for over a year and a half. If there’s a silver lining for NBC, it’s that no late-night talker has achieved the relevancy of its own Saturday Night Live since Trump was elected. Fallon’s old digs enjoyed its most-watched season in 24 years during the 2016-17 season.

High: This Is Us, and That’s That
Greenblatt’s final two seasons at NBC were among his best. With linear ratings in a tailspin for all of broadcast, NBC's stability (and sports) helped it retain its ratings edge. The network launched This Is Us, which proved to be a rare critical and commercial breakout for broadcast drama. (Save Roseanne, it ranked as the highest-rated series on TV.) And, in early September, NBC scored the bragging rights of beating CBS as the most-watched network for the full 52-week TV season. It’s an accomplishment the network managed on the back of a Super Bowl, the Winter Olympics, This Is Us, three Chicagos and a robust summer of reality programming. A repeat of the banner year seems unlikely, but that’s not Bob’s problem.