Phasing a portion of chromosome vs whole chromosome using Beagle?

Question

[alek0991]

I need to phase a gene region (around 100Kbp) in chromosome 13 using Beagle. Does it influence the accuracy of phasing if I just give this 100kbp region as input to the Beagle (Not the whole chromosome 13)?

[Zev.Kronenberg]

Might be a good idea to add 1Mb on either side.