The New York Agreement represents over 86% of hashing power and the economic majority,
so if everything moves according to the agreement, there will not be a chain split.
Here are dates that you need to be aware of:
July 21st: SegWit2X signaling starts.
July 29th: SegWit2x lockin.
Aug 1st: BIP148 begins. This rejects all blocks not signaling for SegWit.
A chain split does not happen if those who agreed to run SegWit2x stick to their word.
At this moment, no chain split looks like its happening