たしか~ The dictionaries say “perhaps” but in reality たしか is more like a “softener” that you put in front of a statement you ARE sure of, but you want to make it more polite/indirect.   $$$
ひょっとして~ This one is more like “could it be. . .? Naw, it couldn’t. . .but..??” Like if you run into someone that looks like your long-lost friend from 4th grade.
(ほうが一) This is usually used for bad things only. “Just in case.”  Kind of thing. “In the unlikely event of a water landing, pull out your inflatable cushions.”
(Start-of-sentence words for “perhaps”)