Bowling Conditions - The Flat Oil Pattern - With the flat oil pattern the bowling lanes are conditioned flat from gutter to gutter or from edge board to edge board. With this pattern there is no taper or crown. It is completely flat. This pattern is very difficult to bowl on. There is no hold in the middle of the lane so the ball will cross over to the other side of the head pin and go out of bounds. If the bowler swings the bowling ball to the outside boards it will just stay out there and never grab the bowling lane. In the illustration below I have the flat oil pattern at 40 ft., but there is no set distance for this pattern or any pattern. The distances are only examples. I believe they use this type of pattern in the US Open Bowling Tournament.
Note: The Illustration Below Shows - A Basic Flat Oil Pattern.