Cape Town - Springbok defence coach John McFarland believes they showed an improved defensive effort in their Test against Wales in Cardiff.The Boks won 24-15 without conceding a try.While they still made a lot of mistakes, the accuracy of their defence improved since their last outing against the All Blacks at Ellis Park when they conceded five tries in a 38-27 loss."Wales only broke the line three times. We kept to our structure and were very physical," McFarland said in an interview with Die Burger's website."The conditions were also very different than in the Rugby Championship. There we and the All Blacks were chasing four tries for a bonus point."You simply have to win these tour games in the Northern Hemisphere."McFarland also praised the defensive efforts of two Springbok forwards, flank Willem Alberts and debutant prop Frans Malherbe."Willem made 19 tackles - which is a massive amount. In most of his tackles he also physically dominated his opponent and drove him backwards. He set the standard with that."(But) the one who impressed me was Frans Malherbe. He made 15 tackles on his debut."The Boks next tackle Scotland in Edinburgh on Sunday (kick-off 17:00 SA time).