Board Thread:Questions and Answers/@comment-118.211.8.204-20150302141811/@comment-27384850-20170318194306

Using two swords without Skill Connect doesn't give him an advantage, though. Sword Skills are pivotal for duels, so to use your free hand on a sword that doesn't get used would be pointless. In fact, it'd probably be disadvantageous because he's removing the ability to use Martial Arts skills (Asuna used one to overwhelm Yuuki). If Kirito had thought that using two swords would give him the advantage he would have used two swords. He didn't because Skill Connect, the sole advantage of using two swords, is very risky and would easily cost him the duel if he were to screw up.