In all seriousness, HAMB doesn't work by simply hitting a million balls, or 10,000 balls or any number of balls.
There's little saying in sports training - practice does not make perfect, perfect practice makes perfect.
Hitting a million balls the wrong way or with bad mechanics, stroke, aim etcetera accomplishes consistency only in being consistently bad. Or consistently inconsistent. If HAMB was all it took, years of experience and playtime would be enough to make people shoot pro level. But that is far from the case.
Pool can learn from other sports. There are experts out there with their own studies, tests, trials etcetera that have figures on how many PERFECT repetitions of something are needed before it is burned into muscle memory and it is truly learned. I've understood it to be around 3,000 or so. About 3,000 perfect, reasonably continuous repetitions. Continuous meaning done with intense concentration, and without taking off any significant time. In other words, 50 reps today, 25 next week, 75 next month. Won't cut it. But doesn't have to be continuous as in non-stop.
This becomes complex, since stance and stroke has many parts and sections to it. It is almost impossible to execute all parts of it perfectly, simultaneously during the process of building up these muscle memory repetitions. It's a good idea to do them in groups. Do groups of things together, things that naturally go together to make it easier. Then tweak the parts lagging behind or not yet mastered. The rest, which is mastered, only needs routine maintenance to keep sharp.
Other pro athletes work with coaches intensely for weeks, even months to adjust just the tiniest of changes in their form, stance, stroke, throw, swing...whatever it may be. They do many thousands of reps. With supervision to ensure it is being done right. This is to force themselves to learn. To make it happen.
Players who have played a long time often think it is impossible to learn to do something a different way, perhaps even a radically different way. It's not. It just takes a lot of work and time. But it can be done.
Maybe I can relate this using an analogy. It's a lot like switching to a new cue. One that is very different. Different weight, taper, balance point, even different type of wrap, with a totally different tip. All factors different. It feels strange. It really does. Uncomfortable at first. Can't help but feel like it might be impossible to ever get the same level of feel and touch with it as you had with a previous cue used for many, many years.
But by using it and nothing else, and playing and playing with it - it becomes familiar and learned. And what was once an extension of your arm, now feels foreign and strange.
There's no short cut when it comes to a good stroke. What I call talent, are those people who for whatever reason, have the physical ability or coordination to be able to put all the pieces together faster, and more correctly during the learning process. People call it 'being a natural' because it almost seems like they naturally get it right. I don't know what the cause for this is, but some do learn faster as a result.
But there isn't a pro out there that didn't put in the time and effort. It comes in different forms. Some did it the academic way, with teachers and doing drills, playing tournaments. Others did it by gambling and playing under pressure all the time against better players.
Whatever the case, there was some kind of motivator pushing them to execute to the best of their ability, over and over. To shoot all those shots the right way. When gambling, your ass gets down on the shot and does the best it can to stroke well, aim well and make the ball. Otherwise, your wallet gets thinner. It's why some like to say that players who gamble get better faster, or are better players. Some players want tournament success. And are fortunate to have good teachers who stick with them and they drill and drill. Learning, tweaking and practicing.
Great play, high level play is nothing more than fundamentals applied. Mastery of the fundamentals. If a player can master the basics found in any number of pool instructional books...and apply them to game scenarios - they will be near pro level. Mastering means, being able to consistently execute these shots and skills to where errors are very, very rare.
As was said, amateurs practice til they get it right. Pros practice till they can't get it wrong.
That's the difference. When is the last time you or any other player got on a table and worked on a single skill, so long and so hard, til they could do it on right 99 out of 100 times if asked? That's why they say you have to love the game. You have to love it so that things like this do not appear like tedious, boring work. So that these things are considered FUN. And done with full desire. Done with plenty of heart. And dedication.
Most often, I and most other players out there...we don't hit every ball like it means everything.