Hitting inanimate objects and hitting combative people are different things.
John once said that he had many students who could hit quantitatively harder than he could. Many of his larger, sturdier students who had also gotten a firm grasp of balance, looseness and dropping could get a greater effect on a heavy bag or pad than John could. However, that did NOT translate directly to ability to effectively hit people. For all their raw hitting power, they could not manage to land an effective hit on John, while he could land lethally effective hits on them at will. As John put it, such students had the equivalent of .44 Magnum striking power that they could kinda place in the general vicinity of the target sometimes, while John had a .38 Special that he could always place right under their chin, or in their ear, eye, etc. (I protested that John's striking was more like a .357 Magnum in that analogy.)
The difference involves more, however, than just accuracy and the ability to place hits properly and with lethal power on a wildly moving person while remaining unavailable to his movements.
Effective hitting has more to do with sensitivity than with any other attribute. There's a certain qualitative "touch" to effectively hitting all different parts of the human body. You hit a person's cranium differently than you hit the back of his neck, differently than his jaw, differently than his floating rib, or solar plexus, or arm, etc. And you hit the same place differently depending on angle, movement, balance, tension, etc. It's not just a matter of power level, striking tool or penetration. It's an indescribable qualitative "feel" for the human body, its movement and density that can be learned only subconsciously and only through lots of experience in touching people (ideally lots of different people) in a combative context with the right attitude at low intensity, i.e. in slow to medium speed contact flow.
It is impossible to learn effective internal striking without training partners. Inanimate objects will not only never give you the "feel" for the moving human body, but the feedback they provide will actually create bad habits and invalid ideas about your hitting if you don't get regular contact with actual live people. To get maximum "satisfaction" from hitting bags, pads etc., you actually need to do things (with regard to tension and balance) that you do NOT want to do in order to hit people effectively.
Hitting effectively is like hitting baseballs. In hitting a baseball, if your timing, accuracy and swing are perfect (or perfect enough) and you hit the ball right at the sweet spot, it feels effortless, yet the ball goes way over the fence. Similarly, effective hitting should feel effortless. This is a major change for people used to hard-style martial arts or who generally have a "no pain, no gain, max effort!" outlook. It takes faith in the Guided Chaos training method to let go of the desire to feel intense feedback within your own body. If your internal measurement of how "hard' you're hitting is how much tension and effort you feel in your muscles and joints as you hit a heavy bag, you'll have to completely let that go if you want to learn how to hit effectively.
Ideally, in contact flow you will learn about hitting from actually hitting people (at reduced speed) as well as from being hit by them. This has to be done at reduced speed. Too much speed won't allow you to feel all you need to feel, plus people will get hurt. Getting hit in a combative context (i.e. during contact flow movement, NOT just standing there and letting someone hit you) teaches your subconscious a heck of a lot about how to hit effectively, as well as how to get out of the way, as long as you accept and move with it with the right attitude (see previous blog post about training partners). Hitting your training partner in contact flow (again, NOT just having him stand there as a target) teaches you a lot as well, as long as you're moving at a constant speed and not trying to "add" anything to your hitting in terms of speed and tension.
Remember that hitting is part of the flow, it's not a separate thing. As you move, the basic principles (balance, looseness, sensitivity, body unity and freedom of action) should imbue all of your movement. At certain points, parts of your skeleton will collide with parts of his. After the fact, you can call these "strikes" or "hits" if you will. However, any attempt to plan or "form" them BEFORE they happen will just screw up your training. Amidst the chaos of real lethal violence, you likely won't know which of your movements will become strikes, or deflections, or off-balancing, or whatever, nor to which targets. Train properly and your subconscious will develop the necessary "touch" to make every movement what it needs to be on the fly.
Once you start to get a feel for internal movement and striking, you realize that if you can touch it, you can destroy it, from any angle, to any target, with just about any part of your body--as long as you don't try to force the issue.
Balance, looseness, sensitivity, body unity, freedom of action, being unavailable yet unavoidable, accuracy and precision in movement are all much more important aspects of effective hitting than what effect your hits have on inanimate objects.
And in any case, never expect any particular hit to have any particular effect on the enemy. You must continue to move with what is until you are able to safely escape or get a better weapon in hand to facilitate your escape.