ON a prop aircraft it is the engine that would be most critical to loose. The downgoing blade gives thrust (power) if the nose is up, which would be normal flight attitude, hence the left engine thurstline is closer to the centerline of the aircraft. This is the engine you don't want to loose(!). The yaw moment if flying on righy engine only is therefore greater.
On jet aircraft it is normally not defined. The wind direction changes and so does your flightpath in the patter, which yould shift the critical engine from one side to the other. Not practical