Best is like Beauty, or favorite it is a personal choice. My personal Choice is One Pocket, but I will admit playing 14/1 by my lonesome for practice, as it is a good way to learn toread racks, learn kick, and figure out how to make balls.
One of the BEST TEACHING AIDS that helps with both One Pocket, and 14/1 is Ray Martin’s 99 Critical Shot Book. Book can be found under 12 bucks.
But you must read cover to cover many times to unlock info you missed first time, then practice what Ray teaches, to see improvement.
Do not buy the book, place on shelf, never read, if you expect to get anything out of it. Or placing under your pillow at night while you sleep , hoping to absorb the info, will yield same results nothing.
JMHO