It's the range issue for me. I just can never get fighters in black range. One time I almost did, but my fighters activated first and blew it up.
You need to be willing to take the first punch, but position your fighters in such a way that the other guy won't get in more than 1-2 squadrons on your Raider before he starts getting engaged. It takes some time to master. You can also do well with positioning a Raider near your a Rhymer ball or some such so those who are trying to engage it and shoot it down get to eat flak. Just make sure you aren't running over your own squadrons.