I believe it's just random, not like for every certain number of bait you get a point. More like a certain % to get a point. At least that's what I think XD
Characters:
R e i - Stalker
Y u i - Priest
BlackRose - Assasin
I actually found it to be quite the opposite as even Pandora said. I fished a lot at the advanced spot and never got 1 point, so I returned to the original fishing spot and got the 50 points there. Don't worry, it only takes around half hour But I returned to the Advanced spot and started gaining points. Just my personal experience. Not meaning to step on any toes GM-Pandora
yeah mu luck is very bad i get about 1 point for about every thousand baits but i still get my pleasant suprises once in a while i love so much so its all good.