Some woven fabrics really are quite a bit stretchier one way than the other.
One can take 'mark off' a ten inch length - stretch it and put it against a ruler to see how much longer it got.
Then 'mark off' a ten inch length going the 'other way' - stretch that and put it against a ruler to see how long it is now.
If the print doesn't matter, I generally prefer the length of fabric.
By the way - when cutting border strips - even fabrics that appear to be an allover print - sometimes have a subtle stripe in them.