Bill Taylor's
book "
Target Lines" :
http://www.[Banned-SpamURL].com/products/49explains how to line up to play any angle on the lane. It was written before plastic balls were invented, so there are some updates needed especially what to do when encountering the ball return, but playing all of the basic angles to the pocket are covered in this
book.
If I was playing a break point of 10 and wanting to cross the arrows at 15, I would need to lay the ball down around 18 which means that since I slide 5 boards left of where I lay the ball down I would need to slide around 23 in order to lay the ball down on 18 and cross 15 to hit 10 at the break point.
The break point is at approx 45ft on the 10 board the arrows are approx 15ft from the foul line, so I am looking to cross 15 which is 5 boards difference in 30 ft. My lay down point is 15 ft(approx)from the arrows which is 1/2 of 30 so I divide the number of boards crossed (5) by 2 to get 2.5 boards my ball will need to cross between the lay down point and the arrows to hit the break point on 10.
Taking the 5 board difference into account my slide should be around 23 to lay down on 18 so I need to maintain that angle at the start of my approach which is 12 to 15ft back from the foul line. To maintain this angle and walk straight to my target line I will need to line up so my slide foot is on the 26 board at the back of the approach and slide my feet toward my target line until I get to the spot where I start my approach. I find this gives me a sense of awareness to the angle I want to go in. So my feet should walk in a line from the 26 board at the back of the approach to the 23 board at the foul line, most starting positions are somewhere in between.
Modern bowling sometimes uses cross over steps if you are one of these types, you are not wrong for doing this, you just need to learn to feel your target line and make sure you are sliding square to it.
Cross over steps happen at the beginning where the right foot (right handed) crosses in front of the left foot to allow room for the ball to pass, the left foot walks to the left to get out of the way of the right foot, the next right foot/power step also crosses over in front of the left foot, the left foot then slides back around the right foot toward the target line. The power step crossing over in front of the left foot allows the hips to clear out of the way of the ball better. Many of the top pro bowlers use this type of foot work. Some still slide on the same board they start on, others drift 5 boards left, but they do the same every time.