I don’t know. On long straight ins I use about a tip of English off center to stop. It’s by trial and error and feel. So, I’m sure I’m subconsciously adjusting my aim. If I try center to center I always miss (for distance). If I were smart enough to describe it,I’d have a website and book. I’m just a dog chasing cars, I wouldn’t know what to do if I caught one.
You're not getting through the ball straight, and are using english to deflect into the proper hit. With a proper center ball hit, and straight stroke along the aim line, english can only reduce accuracy.