Over how many systems do other empires colonies if you have open borders?

[Gilbert95]

About a year ago I've seen someone state the Ai will make up to 5 jumps (i. e. 4 intermediate systems) to colonise a system. I have personally seen 4 jumps (3 systems in-between) in one of my games about 3-4 months ago.

1 jump is fairly common, and I have even seen AI empires jump over unclaimed systems, for no apparent reason! More than one jump is quite rare though.

There was a brief time where it was 5 as the devs were experimenting with what works well. It quickly became obvious this was too much and they dialed it back to 2. This means the AI will put outposts on systems upto 2 jumps from a currently owned system.