Centerball is the best way to hold the cue ball (stop shots, soft rolls, soft stuns). Spin is the best way to move the cue ball around. TOR Lowry is a centerball fanatic, and in his video on Center ball training he even confirms that spin is a more accurate way to control speed and direction for cue ball movement (45:47-46:33 on this link:
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How much spin you need depends on if you're playing a hold game or a move game. Straight pool and 8 ball are hold games. You will use mostly center ball. Spin will still be needed to move around though, and those situations are often the critical transitions that will take two 4 ball runs and turn it into a complete table run. I'd say you use spin in 8 ball about 25% of shots.
9 ball and 10 ball are move games. You can't pick a pattern to work around movement, you have to do what you have to do. Here you'll be using spin on 50% of your shots on average.
I truly believe if more people quit screwing around with their fundamentals and learned to spin balls with a soft touch they'd play much better. You don't need a powerhouse stroke with laser accuracy if you have ball in hand shape on every shot, and that is what spin unlocks for you once you learn how to use it correctly and assemble the right patterns and angles.