From: PDX (and now) London, UK
I don't know about y'all, but if I'm sweeping I'm doing it at an altitude below what I think the maximum is for the CAP. However, if I come in too low and the CAP's too high, there may be no engagement. Likewise if I come in too high and the CAP's too low there may be no engagement. If you're using Sweep as a tactic, and no engagement occurs, that is what some people call a failure. Attrition may go against you on any given day, but if it is the right tactic to use (you desire to achieve air superiority and you believe you have the means to do it) attrition is what happens. Don't try to be too cute. The only reason to sweep at max alt is because you don't have air superiority or any hope of getting it but just want to stir things up so maybe some of your bombers get through.
Why would you sweep at an altitude lower than the highest CAP? Don't you then have the CAP gain the dive?
I've not experienced the CAP not being engaged by even a 42k sweep so far, and the next test has the highest CAP at 9k.
Well, I have experienced having CAP too high and not intercepting bombers, much less sweeps. My position stands.
edit: I've also experienced having my sweeps too high and not encountering CAP,
Definitely, I've had this happen with bombers for sure. Sweeps seem a different thing though.
"Success is the ability to go from one failure to another with no loss of enthusiasm." - Winston Churchill