OtterCuber
Veteran
Look, I like your idea here, but you do NoT need to know full OLL to be sub-20. And he does not need to go through an algorithm sheet. Or even know how to use look-ahead.
Listen, @SteelyTheCuber, you just have to learn how to do advanced F2L fast and full PLL. Then go through some vids on how to do finger tricks for F2L. THEN you do about 500-1000 slow solves to drill what you learned and 1000-2000 times solves to see how much forward progress you have made. Only then have you broken your curse.
GenTheThief is a respected member of this community. His suggestion is certainly good, too. Remember, there are many paths to success.