LAWRENCE, Kan. — Kansas freshman Johnny Furphy has one thing on his mind before every game. His defense. You see, offense comes naturally to the guard from Melbourne, Australia, while his defense is still a work in progress. According to his mother, Liza Alpers, Furphy thinks long and hard about KU’s defensive schemes before and during each game. Perhaps that thought is paying off, as Furphy delivered his best all-around game against the nation’s No. 4-ranked (and KenPom’s No. 1-ranked) team — in a 78-65 Kansas win over Houston. The Jayhawks, ranked No. 8, were rare home underdogs at Allen Fie…