IMO, it's all back to what we need to do. I was told by somebody who teach me playing pool long time ago, to always keep my tip near the center of the CB. Then a year after I moved to another province, another guy show me how he hit with ton of english (mostly like Wu Chia Cing do). It's all nearly (again nearly) the same, it's depend on where whe want to place the cb but still avoiding contact with another ball, how confident we stroke using how much the english and how well we know our cue will deflect to compensate it. I can stroke nearly 3 tips of english, but only when needed, so do we. Just my opinion.