Lateral position when drafting

Is the draft behind a rider only applied directly behind a rider or does it apply laterally across the whole road? 

Aka, if I’m on the left side of the road and a rider is on the right and my front wheel is at his back wheel, am I in the draft or exposed? 

I’m expecting to be exposed, but given Zwift has no way to control lateral position, I thought maybe there is a chance the draft applies across the whole road.

I think that your last comment is how the draft should be applied.  Since we have no control over our lateral position the draft should apply equally all the way across the road.

watch your avatar.