I have never watched The Big Bang Theory. That’s an especially surprising admission considering that I love multi-cam sitcoms, Bob Newhart, and Star Wars. The Big Bang Theory is a multi-cam sitcom that has, for the past 6 seasons, featured Bob Newhart as a Force Ghost à la Obi-Wan Kenobi. You read that right: The Big Bang Theory has been airing episodes designed specifically for me, ones so squarely situated in the Venn diagram overlap of my interests, and I had no idea.

Until now. Okay, until, like, a year or so ago when I finally saw a GIF of my comedy (and style) icon in full Jedi regalia waving a lightsaber around. What have I been missing?! Turns out I’ve missed out on Newhart’s biggest TV role of the 21st century–that is, if you’re not a fan of TNT’s The Librarians or don’t count his truly devastating ER storyarc. Newhart’s role as Arthur Jeffries, a.k.a. Professor Proton, is most likely how millions of millennial TV viewers know him. If I’m ever gonna connect with these young’uns and try to get them to watch Bob as Bob Hartley or Dick Loudon, I need to know him as Arthur Jeffries too!

So with Newhart’s sixth and final appearance as Professor Proton having aired, I’ve gone back and watched my very first episodes of The Big Bang Theory with one question in mind: which episodes are the most Newhart-focused?! Below you’ll find all six of Newhart’s appearance on The Big Bang Theory (apparently he’s also popped up on Young Sheldon but I’ll stick to one show I know nothing about at a time) ranked by how much screentime this comedy legend has per episode. Which Big Bang episode gives you the most Bob?

6 "The Planetarium Collision" (12x5) This episode from just a few weeks ago ensured that The Big Bang Theory would go out with a bit of a Bob bang. Of course a sitcom’s gonna work in another appearance from all its fave recurring characters during it’s final season, and when you have Bob Newhart on speed dial, you get him in one more time! Bob’s final appearance as Arthur Jeffries is another dream/vision unfolding in Old Sheldon’s subconscious. The two quick scenes take place in a deli on Dagobah, the swamp planet from The Empire Strikes Back that’s home to Yoda and at least one bog monster with an aversion to eating androids. This time around, Bob–I mean Arthur–gets to give Sheldon marital advice following a blow-up with his wife, Not Blossom. Arthur’s primary advice to Sheldon: “Whatever you do, don’t order the reuben!” His real advice, though, is “don’t go to bed angry,” which is also the premise (and paraphrased title!) of a solid Bob Newhart Show episode. That’s the kinda deep-cut, probably unintentional Bob Newhart content I’m looking for in these episodes! But while that reference is great, as is Arthur’s angry “does this look ‘lean‘ to you? I ordered lean!” line, there’s not a lotta Bob in this episode. But whatever–Bob was 89 when he shot this episode! These 97 seconds of screentime are a marvel! Big Bang Total Minutes: 18:58

Bob Minutes: 1:37

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5 "The Proton Regeneration" (11x6) The show snuck in another Newhart appearance last season, giving us just a tiiiiny bit more Bob time than his Season 12 visit. In this one, Bob (wow, it is impossible to refer to him as “Arthur,” I’m learning!) returns to Sheldon’s subconscious to help him out with a relatively minor dilemma: the old Professor Proton show is getting rebooted and afraid-of-change Sheldon is freaking out. First Ghostbusters, now this?! Things get even worse when Sheldon realizes his audition tape was ignored and the producers cast Wil Wheaton (who I now know plays himself as a character in the BBT-verse). Compared to all the other advice Sheldon gets from his dream Jedi master (one who is, as Sheldon puts it delightfully, “kind of an old crank”), this one-on-one chat seems pretty low stakes. But while the conflict may be mild, you know what isn’t? Bob’s fiery delivery! His increasing exasperation at being summoned up every time Sheldon has a conundrum is great (“What part of ‘rest in peace’ don’t you understand?”). Another great detail: the episode ends with Arthur telling Sheldon “We could also meet in a deli,” which is exactly where the next meeting (see above) takes place! Continuity! Still, not a lot of Bob in this one! Big Bang Total Minutes: 21:31

Bob Minutes: 2:25

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4 "The Opening Night Excitation" (9x11) Flash back a little bit further and you get this Season 9 episode which, I gotta say, is the wildest of Bob’s bunch of Big Bang eps. The A-plot is all about Sheldon and Amy (a.k.a. Mayim Bialik, a.k.a. Not Blossom) deciding to do it and following through on that decision. The B-plot is all about the rest of the boy Bangers (that’s what they’re called, right?) freaking out about the release of Star Wars: The Force Awakens (in this, I relate to the Bangers). Force Ghost Arthur’s got his work cut out for him in this one: first he has to convince Sheldon to hang out with Amy instead of seeing Force Awakens on preview night (a legit terror that I, a huge Star Wars fan, completely sympathize with!). Then Arthur has to–brace yourselves!–give the virginal Sheldon advice on making whoopie! That’s when imaginary Jedi Arthur tries to impale himself with his imaginary lightsaber. There’s 2-3X more Bob in this one as the previous two, and the “I can’t believe I just heard that” plot makes this one really standout. Seriously, I can now recall the sound of Blossom shouting “Let’s get me waxed!!” whenever I want. That’s… that’s something. But also, this episode gave me the bonkers sight of Newhart stabbing himself with a lightsaber, so it holds a special place in my heart–even if it also showed me what post coital Old Sheldon looks like. Big Bang Total Minutes: 21:27

Bob Minutes: 5:06

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3 "The Proton Transmogrification" (7x22) Here we are, the turning point of Bob’s tenure as Arthur Jeffries! After appearing in two episodes as a living, heavily breathing (why the hell do the Bangers not unionize and demand their apartment building fix that busted elevator?!) former kids’ show TV host and mid-level scientist, The Big Bang Theory killed off Bob’s character. In this Season 7 episode (wow, this show has been on for a long time!), Sheldon and his science frenemy (?) Johnny Galecki learn that their childhood hero has passed away. Galecki tries to comfort Sheldon, but he has no time for that. It’s almost Star Wars Day (May the Fourth) and there’s an Admiral Snack-bar to tend to. Sidenote: there are two ways for BBT to get me to laugh, one being anything said by Bob Newhart, and the other being groan-worthy Star Wars puns. By that metric, this episode delivers. Sheldon bails on Arthur’s funeral, leaving Johnny Galecki and Kaley Cuoco to go it alone and miss Star Wars Day. To deal with his repressed feelings of grief, Sheldon’s subconscious conjures up a vision of Arthur during a dream. Even Sheldon’s brain’s version of afterlife Arthur isn’t jazzed about this (“I was hoping I was going to haunt my ex-wife.”) And when Dream Sheldon realizes this is totally an Obi-Wan Kenobi sitch, Bob goes full Jedi. His response to all this Star Wars lore talk: “Is… is-is that an Internet?” Arthur Kenobi helps Sheldon process his feelings of grief, and Sheldon wakes up and gives Galecki a big hug. As you’ve seen on this list already, this is far from the last time Sheldon would seek advice from a dream version of a Jedi riff on his childhood hero. What a show this is! Big Bang Total Minutes: 21:19

Bob Minutes: 6:11

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2 "The Proton Displacement" (7x7) Can I just say how much I love the applause breaks Bob gets every time he appears in one of these initial guest appearances? I love them. He deserves them! Here’s one of the two episodes on this list that features Bob Newhart playing actual Arthur Jeffries (guess where the other one ranks?). In his second appearance on the show, Bob gets to do a whole lot! We see Arthur Jeffries do things like fill a prescription and conduct experiments on vacuum tubes or something (wait–is this a reference to Jeffries tubes on Star Trek? I think… wow, I think that reference is so esoteric it deserves my respect). We also get to see Arthur’s front porch (Sheldon shows up to badger his onetime hero for picking Galecki as his junior science bro), the closest glimpse we get of the curmudgeon’s personal life. What’s really great about this episode, though, is Arthur’s barely restrained anger towards Sheldon’s science ringer, Bill Nye the Science Guy. The best part of the episode is when Nye tells Jeffries, “My show never would have happened without yours!” Arthur: “That’s what I told my lawyers!” This one’s a real winner when it comes to giving Newhart plenty to do. Big Bang Total Minutes: 19:41

Bob Minutes: 9:26

47.9% BOB Buy The Big Bang Theory "The Proton Displacement" in iTunes