Hmmm. Let me Think

OK Im just wondering..Someone explain this if you can.

Mary J Blige says in the song "The One" feat drake

**I aint saying Im the Best but Im the Best...**
What exactly does she mean. Because she says she isn't saying she's the best but then she states that she is the best. It's like contradicting her previous statement if you ask me but IDK?? I love that line by the way but I'm in Lala land when it comes to it's meaning.