Due to the physical action of the balls and the common nature of many of the shots' (the cut angles being close to the same over and again (though, yes, ball positions differ somewhat from stroke to stroke) the three speeds of 1) soft, 2) medium and 3) hard, work quite well for most shots.
For example, many times when you need to halt the cue ball following impact, a medium stroke will suffice. When the cue is close to another ball, a gentle or soft stroke taken near the middle of the cue ball works just as fine...
And on many long distance, angled shots on an object ball, medium or average speed for you will be the key. Please review the previous page of this article on why and when to shoot medium speed if you don't already know this pool principle before reading on.
I think you will realize you cannot be successful using 3 speeds only for other stick-and-ball sports such as golf, baseball, tennis and more. But those lovely little walls on the back of the billiard pockets help sink balls struck harder than needed to drive them to the hole.
Plus, the four cushions surrounding the pool table's cloth also help reject hard struck cue balls back toward the table's middle. Imagine a low wall behind a golf hole, attached to the putting cup, and four walls surrounding the green and retaining balls struck too hard on the putting green, and you'll get my meaning for pool.
2 Speeds You Should Not Employ In Billiards Competition Do not play "super soft", "super hard" (or any other stroke you "wouldn't normally do" or comfortably do) on any of the first balls of the game. If you can't pull off cue ball speed with ease, do not attempt it. Stick to medium (for you), soft (your version of soft) and a hard stroke only (a hard stroke needed only rarely during any billiards game).
If I can get you to ignore super soft and super hard strokes, and narrow your focus to choosing from among three speeds at the table only, you'd be in great shape (cue ball shape position pun intended) for pool.
Why did I say to avoid abnormal strokes on the "first balls of the game?" The answer may surprise you. Can you guess what I'm going to share before you click/turn to the next page of this article? Think about it for a minute before moving on to better billiards competition than you've dreamed of before.