Take the bank calculation with a grain of salt as english derived from impact with the cue ball on any oblique angle or with the stroke can affect the path of the object ball. Draw or topspin and speed also effect the bank stroke.
Bank shot calculations as indicated are correct for any one rail bank--if the cue ball is spinning into the cushion at time of impact.
Having said that, you can do the calculation for any bank faster than you read it on these pages. A mere ten minutes' practice drawing these imaginary lines with the aid of a cuestick will save you hundreds of times in future bank opportunities. The banks are now open!
