Probe vs. Full Scale Attack

[paullus99]

What is the best way to structure a probe/diversionary strike vs. a full-fledged attack?

We all know that it is better to attack multiple areas in a turn (if you are able) to spread the defense & mitigate the reaction moves, but I feel there is a very fine line between what would be considered a mere probe and a full-scale offensive attack.

What would you guys consider to be a good ratio - to tie down an enemy force, while not over-committed and suffering major losses?