According to Freddy "The Beard" Bentivegna in his book, all great bankers have one thing in common:
they try to stay on the vertical axis of the cue ball whenever possible
Most bank shots should be hit with one tip of follow for consistency. The cloth, the rails, the humidity, the balls themselves, and other things like position can change the angle and the degree of English that may be needed.
Most of us know that "follow" lengthens an angle, and that "draw" shortens it. Similarly, inside or reverse english tightens a bank, while outside or natural english widens it.
On a long slow bank (without english), at pocket speed, the "collision induced throw" will sometimes ruin a well-hit bank shot. All that might be needed is one tip of the correct english to overcome this but that's not always so.
I highly recommend Freddy's two books, "Banking with the Beard", and the "GosPool" to anyone who's serious about the subject. The best bankers like Bugs and Grady have all praised it and acknowledged the secrets contained in it.
Oh, by the way, if anyone ever has any doubts about the banking knowledge of Freddy, or even the players in Chicago in general, just go to North Shore Billiard Club and get in a game of Banks or One-Pocket . They take banking to a whole other level.