yugi's grandpa owns a card shop so he has access to a shitload of cards, and before his matches he does research on his opponent's deck. (hence his match against kiba where they both tried to get three monster tributes to summon god cards and also prevent the other from summoning their's. thats a stratagem he wouldn't use against... like mai, against her he would focus on beating wind attribute cards.
yugi's grandpa owns a card shop so he has access to a shitload of cards, and before his matches he does research on his opponent's deck. (hence his match against kiba where they both tried to get three monster tributes to summon god cards and also prevent the other from summoning their's. thats a stratagem he wouldn't use against... like mai, against her he would focus on beating wind attribute cards).