He's a child prodigy and a natural genius. Several characters have stated so and Sasuke has yet to fail to take apart an enemies technique since part one. How many characters have acknowledged him:
- Jiraiya called him a natural prodigy.
- Orochimaru called his own genius pitiful before his.
- Kakashi called Sasuke a genius and gifted several times.
- Shikamaru looked up to him.
- Lee Said that his genius surpasses the imagination.
- Chee called him a rare genius etc.
Feats:
- Creating his own chidori variants.
- Perfecting Uchiha Katon attacks on his own at a tender age of 7.
- Perfecting Kenjutsu, Ninjutsu, Shurikenjutsu and his control over Senjutsu in mere (about) 3 years.
- He has made several quick-silver strategies through out the manga:
- Haku.
- Sound Ninja.
- Gaara.
- Deidara.
- Orochimaru.
- Danzo.
- Itachi. etc
By and by, I'll give him 19 out of 20. I am only cutting one mark as he's not as experienced as most. But he's one of the smartest characters in the manga. If you disagree, then you are going against the manga.