Full disclosure: I’m a Gary Oak supremacist. I loved his game counterpart, the OG Blue, and have ever since. In the anime, I loved his style, his brand of arrogance, and his team was way cooler than Ash’s. So I nodded along when I read Daniel Dockery’s piece for Crunchyroll on why Gary Oak was right:
It also doesn’t help Ash’s case that Gary beats him in battle during their first match. After winning the Orange Islands championship, Ash and Gary duke it out in a long-awaited duel, but Gary’s Eevee absolutely runs through Pikachu and all Ash can do is follow Gary into the Johto region. Ash finally gets his win back during the Silver Conference, but once again, Gary doesn’t try to pull anything nor does he get connivingly desperate at the end. Instead, after the match, he opens up and talks about why he takes not winning so harshly and even acknowledges Ash’s good work.
Gary also shows emotional growth and perspective in ways that some other characters could never. At the end of the original series, Gary reveals that he doesn’t want to be a Pokémon trainer anymore. He wants to be a researcher. For someone who can’t stand not being the best all the time, it’s a pretty solid judgment of self — though one could argue that, dude, it’s just Pokémon. Get over it. Though Ash Ketchum is certainly commendable for his ability to be knocked down and get back up, Gary Oak realizing that what once was his dream doesn’t quite hold the same appeal for him is fairly mature. Especially when you compare him to the kid who once had a whole cheerleading squad follow him around to make sure his every move was received like a touchdown.
Perhaps Gary’s shock early exit from the Indigo League finals puts a dent in the argument, since Ash got to the last 16, and there could be a counterargument that Gary left competitive battling for research because he couldn’t win when it mattered in league tournaments (for the record, I do not subscribe to the adage ‘those who can do and those who can’t teach’). But Ash needed Gary as the proverbial carrot—or stick—to get him as far as he got in the early series. And no other rival has had the same edge in my opinion.