Sounds like what you are running into is a variation of a reverse block. That is where oil is out the outside and dry on the inside if you didn't already know. Most all houses would never put out a reverse block because its hard to score on and the bowlers wouldn't appreciate it. This lead me to believe that you are bowling after either a kids or seniors league has bowled followed by a men's or women's league. The lanes start off normal usually a wall or taper. The first league of the kids throwing plastic balls down the middle takes a bit of oil out of the middle of the lane. Not much but it pushes it down the lane (carrydown). The next league which is the mens league is probably using strong equipment which will absorb oil off of the lane, they will most likely be playing inside because the kids have pushed the oil down the lane. This takes even more oil out of the center of the lane. Soon enough you have a little reverse block on your hands. The best way to play a reverse block IMHO (and if you have a good amount of revs) is to use a little of the lefties oil (if your right handed). Let the ball skate through the oil on the lefties side of the lane by moving very deep and throwing the ball out over the 6th to the 5th arrow. Use a ball that will have a nice controlable arc (flip is the last thing you want on this condition). Now if you dont put many revs on the ball the best way to play it would be right up the oil with an aggresive ball. Accuracy is really key on this shot. I wouldn't lose the hitting power by using a plastic ball up 15. I'll never forget when I first saw this condition, I think I shot about a 479 and that was in a tournament, it really made me learn how important accuracy is if you want to cash in tournaments. Hope this helps you out a little.