everyone only fights the #1 contenders. silva has faced the best fighters UFC has to offer him in his division, and a former good one in forrest griffin. you can't say guys like koschek and maia aren't great fighters. silva has fought the best that he can fight while under contract, and until that changes, he's defended very well - he's just so good that great fighters look stupid. just like gsp. he's fought great fighters, but just makes them look bad.