IE a character can only be as smart as the writer.
E1: Warhammer is really, really bad for this trope. Characters are presented as strategic geniuses or tactical masters, and then when the writer goes to show that off they do some shit like head on human wave tactics assault against fortified positions
Horus in the first few Horus Heresy books is a great example. The other characters spend a LOT of time circle jerking how smart and talented their dad is. Then every single time Horus directs a battle his gameplan is “Loken, go around the enemy, Abbadon, rush B no stop.”
E2: Sister Sage is presented as a mastermind genius in the boys, and is revealed to have been behind everything that led to homelander gaining control over the country, and the season even ends with her outright saying “all according to plan”
The issue is that she just disappears and isnt mentioned again until the very end when she goes “yep I did all of that it was all my plan”
The show doesn’t bother to try to explain how all of the completely random chance shit that happened was manipulated or controlled by her. They present is as a complex chain of dominos that she set up, even though any rational person could tell you that half of the events of that season were unpredictable complete chance events.
E3: Holdo, The last Jedi. The rebel fleet is about to get demolished, Poe and the gang are doing crackhead mutiny shit to try to survive, it’s revealed at the very end after Poe and his team fails that Holdo had an uber plan all along and simply didn’t feel the need or desire to tell anybody in her actively mutinying ship. Dumbass character logic and the movie fully presents it as a “live and learn” moment for Poe even though it would be irresponsible NOT to try to take over command and make your own future when your commanders entire spoken plan is “we’re just gonna fly away until we run out of fuel idk what else you want us to do”
Edit: more examples for the people mad at me for posting sister sage.
Honestly there’s about two dozen Warhammer examples I could give off the top of my head but it would be the same shit with a different smell
BBC Sherlock, asspulls that don’t have a logical connection. The show goes the route of “Sherlock sees or knows something implicitly that the viewer couldn’t possibly have known.” I believe a good mystery is something that the viewer can put the pieces together themselves alongside the author and then after the fact look back and go “oh how did I miss that?” Sherlock doesn’t do this but rather has Sherlock pulling some innate knowledge that wasn’t ever shown or revealed.
House, but in a positive way as the writers made it entertaining, and also borderline subverts the trope by acknowledging its own bullshit (three stories episode where a student asks him why it’s expected for them to have an innate understanding of the dosage calculations for juvenile American rattlesnakes off the top of their heads and house tells them to get good)
A recent trope example of this that I’m hesitant to put in the same category since it’s based off a real life person is The Zuck from Social Network. Half his character dialogue is shit like a character being like “this feels room temperature” and then he would interject and be go “70.7.” And when the other character says what he would be like “the temperature is 70.7, this is 0.7 degrees higher than room temperature.”