Well like the title say you will learn how to find your opponent weak point:

The first step to do that is seeing what kind type of deck is your opponent deck like saying he has a Dino Rabbit deck

The second step is watching all the moves he do in his duel like saying he has 3 cards in the background and one dolkka

The third step is trying to ''remove'' the other cards and try to make your move like if you have in you hand six cards (heavy storm , dark hole , tour guide , monster reborn, bls , ryko , he still have the same field like in the other explanation) now you are thinking what cards are in that background now you think one of those are solemn judgment cuz is a good card the other is starlight road and the other is just a spell to trick you now a nice combo is using dark hole then you set ryko cuz you need to destroy the other cards and then you end your turn , why you did that and you didnt use heavy storm , because you know solemn judgment or starlight can negate that

The fourth step is trying to guess his next move before he play is kinda impossible if is not a net deck but like you know most of the people use net deck (i dont know why but they do) and you already know the cards in that deck now you will find a way to use your cards right when is your turn and find a way to make a good combo or just try to continue the duel if you dont have a way to ''remove'' the other cards

The fifth is just a tip before you start the duel put good cards in your deck with nice effects and that stuff like if you know you will duel a chaos deck you can put a macro cosmos or other card like that just to stall your opponent or putting support for your deck like if you are using a constellar deck you will try to put support but you will add cards who can give you a good help if you dont have something like pot of avarice (this is just example) like you only have a pot of avarice in your hand and you have 11 monster cards in the grave that would be a good boost (if you get the right cards :3 XD) cards like that help to much in any deck so keep in your mind you will get only good support in your deck not only for your monsters also to stall your opponent deck

i dont really know if this would work but it work alot of times for me so cya ^.^

Nice