AdrianS and Billy Ray, this is a great topic! I first heard this philosophy from Lucky Lefty when I first started reading reviews on Ball reiviews, a few years back. It is some of the best advice I was ever given.
Drill strong balls weak and weak balls strong....excellent. It just gives you great variety of angles in which to attack the lanes. I have never forgotten this, and continue to do it these days.
Case in point, I bowl with a buddy who maxs out every ball he's ever bought. Consequently, every ball he owns is drilled 3-3/8 x 3-3/8. When he hits a truly tough condition, then he has made himself totally cover dependent. If he didn't happen to bring a ball along with the right surface, that allows him to score.......he don't score! Feast or famine! No in betweens.
Following the philosophy that you we're talking about now will allow you to set up an arsenal of the same ball, and play in and around the track area, as well as score from multiple lines. And.....I've found it makes the game a whole lot easier, too.
--------------------
Duct tape is like 'The Force'. It has a light side and a dark side, but it still holds the universe together.
Some days you're the bug; some days you're the windshield.