Some online video players give you the option to add or subtract delay e.g. by ±0.5s to subtitles to manually sync them to the video currently playing. However I become functionally dyslexic when it comes to actually figuring out how much delay has to be added. I end up randomly adding or subtracting delay and make it work through trial and error.
Is there some rule of thumb I could follow instead to systematically sync subtitles?


I think the problem arises mostly from trying to add subtitles to arrrr creatively acquired videos where the settings of the creator were not adhered to in the strictest sense.
I mean, I totally wouldn’t know about that myself, I just heard about it online.
It also arises simply from digital copies of DVDs that don’t come with subtitles. Which I unfortunately know too much about.