Mark is great, and so is his book, Play Great Pool. These are excellent videos!
I do disagree with something he says in the first video, when he compares driving a car to aiming a pool shot. Sometimes I wonder how great instructors tend to overlook the reality of learning how to play. They all seem to focus solely on cue delivery, ignoring the fact that aiming itself is also a skill that must be developed through repetition.
Imagine this.... Let's say a new player develops an excellent and consistent stroke without ever shooting a shot, using only the cb, no object ball. Once the player is able to deliver the cue with near flawless action, move onto actually pocketing balls, to sending the cb where it needs to be in order to send the ob to the pocket. There will be no magical pocketing skills here. The player will have to shoot many many shots, estimating or guessing the shot line based on ghostball, contact points, fraction, or whatever, until they develop some type of consistent shot recognition and accuracy in aiming with that nice stroke delivery.
I agree with Mark when he says there are no secret "professional" aiming systems that will turn a player into a great player like magic. I agree when he says cue delivery is the most crucial/important element to playing great pool. But I respectfully disagree when he says a player must miss thousands of balls in order to be get good at aiming. Yes, it does work. I'm not saying it doesn't. It's called rote, and many worldclass players have evolved using that good old trial and error process. But that doesn't mean it's the only way. Thinking that we all have to miss thousands of shots in order to develop consistent aiming skills is just incorrect.
The brain learns and develops skills through repetition. That's why, traditionally, it takes so long to get really good at pocketing balls. First you must develop a consistent stroke, through repetition, then you must develop good aiming skills through repetition. Once you get to the point when you're making more balls than you're missing, your brain is getting more successful repetitions, and that's when your skill level begins to climb quicker. Until then you're repeating more unsuccessful shots than successful shots. That's why you have to miss thousands of shots before the brain finally gets enough solid information to tie it all together, to pave all those synaptic pathways needed to make aiming feel more automatic and natural. A solid and accurate aiming system can drastically decrease the amount of time required to reach this level. By reducing the amount of shots you are missing (due to inadequate aiming experience), you can immediately provide your mind with more successful results, which paves those synaptic connections much quicker.