The title is a little grandiose, but this isn't going to be a post with a strict plan or loads of cited research. I'm going to forego the background of explaining the assumptions, so anyone who is curious about the scientific evidence behind these statements will have some extra reading to do elsewhere.

First and foremost, you absolutely do not need to worry too much about the arm action of a 6U athlete.

6-year-olds typically find 3-pound weights to be quite heavy, so obsessing over a child's shot-put throwing style, for example, is an exercise in frustration. Patience is going to be your friend because trying to correct a "bad" arm action with mechanical cues and excessive or unhelpful feedback simply won't work.

Put yourself in the mindset of a young athlete. Some guy is telling you that your arm needs to here and do this. You are trying. It is not working. Occasionally, he says, "Great job!" Occasionally, he says, "No, like this." You don't understand the difference. To you, it looks and feels the same. Great, now he's saying, "Reach back!" and "Finish!". You're pretty sure you did both.

There are three common paths out of there:

• You luck into a good enough arm action that the coach shuts up.
• You get frustrated and eventually tune out the coach.
• You focus on your arm being there and doing that instead of just throwing the ball.

The most unlikely scenario? The kid executes and repeats the internal mechanical cues perfectly and instantly has a prettier arm action.

Is that prettier arm action the path to future success, though, or is the kid now too focused on arm action instead of throwing? Did you just put a restrictor plate in that kid's engine?

In other words: even if it works, did it really work?

The most important thing you can do is keep it fun because that's the real purpose of the game.

So now you've promised yourself that you won't nitpick arm actions or teach "mechanics" to smaller kids, but now what? How can you help them develop without the risk of doing more harm than good?

The real answer here is that you can leave the 6-year-old alone to play the game. As kids grow and develop, a lot of early athletic development issues, like a wonky arm action, work themselves out naturally.  There's some survivor bias in that statement, since the kids that don't work it out don't tend to keep playing, so what can you actually do to nudge things in the right direction?

Keep the cues simple:

• Throw it hard.
• Throw it where you want it to go.

Create micro-games like target and distance challenges. These can range from gamified catch, to landing throws in buckets, to measured long-toss. Sometimes simply playing catch at the right distance is enough.

The last bit of advice I have to share here is to be careful not to make micro-games too competitive. No one wants to finish last all the time, and the wrong kind of competition could drive a kid away before they have a chance to develop. Sometimes kids need to compete with each other, but the real competition should be focused on improving scores/results over time.

Keep it short. Keep it simple. Keep it fun.

One of the most commonly cited reasons for spending big money on youth travel baseball is "exposure". In most cases, this is an empty promise from the team unless you've been blessed with the ability to play for a team with truly elite talent that competes on a national level at a tournament like Perfect Game's East Cobb Invitational where MLB scouts and college scouts will actually be.

Even if the promise of exposure is actually kept, you have to ask yourself: how much is that exposure actually worth?

If the athlete hasn't reached high school yet, is there any value at all? After all, if you aren't any good at 16, it doesn't matter how good you were when you were 12, and if you are good at 16, it still doesn't matter how good you were when you were 12.

Are tools present that will impress a scout? Kids without a single standout tool are frequently convinced that all they need is exposure because they are good youth baseball players. Without standout power, speed, or throwing velocity, you will simply blend into the game. Scouts are after guys that will perform at the next level, not guys who perform at their current level.

The types of player that are helped by "exposure" are late bloomers, elite athletes that changed sports in high school, position players transitioning to the mound, and a very narrow subset of fringe players that scouts haven't made their minds up about. More athletes think they are in that last group than reasonably should.

If you have the talent to be noticed, scouts will find you wherever you are. It's their job, and the internet is making it easier than ever for them. Your tools are all the exposure you need.

None of this is an argument against paying big money to play travel ball. Just don't do it for "exposure".

Author Mark Hyman of The New York Times recently published an article about two studies that have shown curveballs are no more stressful on the arm than fastballs. Hyman uses this information to openly question the wisdom that says curveballs are bad for young arms. [Click here to read Hyman's article in full.]

The chief problem with Hyman's article is that he seems to misinterpret the study's conclusion. The study found no link between curveballs and injuries, but Hyman appears to have interpreted this to mean that curveballs conclusively do not lead to injury. This is a logical fallacy.

It's unclear whether Hyman has an opinion of his own, but he did seek the opinions of Dr. Glenn Fleisig and Dr. James Andrews. He offers these opposing quotes from Dr. Fleisig and Dr. Andrews about the studies.

I don't think throwing curveballs at any age is the factor that is going to lead to an injury.

Dr. Fleisig's quotes in the article clearly indicate that he doesn't believe throwing a curveball is any worse than throwing fastballs or change-ups. They may be taken out of context, but Hyman sure makes it seem like Dr. Fleisig is very confident with this position.

It may do more harm than good -- quote me on that.

Dr. Andrews, on the other hand, seems to have a deeper understanding of what the studies actually reveal. While the studies did not reveal an obvious link between curveballs and injuries, Dr. Andrews recognizes that a link may still exist outside the scope of these studies.

Obviously, a more stressful pitch is more risky than a less stressful pitch. That's just not all there is to it.

The two recent studies were inspired by a study published in 2006 by Dr. Fleisig, Dr. Andrews, et al. That study's clinical relevance was summed up in its abstract:

Because the resultant joint loads were similar between the fastball and curveball, this study did not indicate that either pitch was more stressful or potentially dangerous for a collegiate pitcher. The low kinetics in the change-up implies that it is the safest.

Essentially, this means that the slower your arm moves, the safer the pitch. This principle carried over into the follow-up studies on youth pitchers, and it's the main flaw with all three.

The studies measure raw joint torques but they don't account for basic mechanical or functional differences between the pitches which already vary from pitcher to pitcher anyway.

The key factor that is essentially unaccounted for in these studies is forearm action - pronation versus supination. A properly pronated pitch is not equivalent to a supinated pitch no matter how similar the kinetic measurements may be.

The muscles of the flexor-pronator mass can provide support against the valgus force that damages the ulnar collateral ligament (UCL). When a pitch is thrown with the forearm in a supinated position throughout the delivery - as most pitchers throw their curveballs - these muscles do not provide the same support for the UCL. This makes UCL tears more likely even if there is no difference in the measured stress levels between pitches.

Additionally, powerful pronation through release helps decelerate elbow extension and helps prevent the olecranon process from slamming into the olecranon fossa on the back of the elbow. When the elbow slams closed it can lead to inflammation of the hyaline cartilage and excessive bone growth including lengthening of the ulna, bone spurs, and bone chips.

When a supinated curveball is thrown, a pitcher risks injury in a number of ways. Without paying attention to what the pitcher is actually doing with his body, these studies simply do not reveal much. They certainly don't give carte blanche to start flipping curveballs like they're going out of style.

Pitching coaches are charged with two main tasks: to improve pitch quality and to minimize risk of injury. Unfortunately, most coaches can do either or neither but not both. The demand for pitching coaches is far greater than the supply of good pitching coaches. The obvious result is a large number of pitchers learning from coaches who are simply not good.

The primary deficiency of most pitching coaches is education. There are countless pitching coaches in youth and amateur baseball who are hired simply because they played professional or semi-professional baseball. This undoubtedly looks good on a resume and is great for marketing, but it says a lot more about the coach's ability to play the game than it does about his knowledge or ability to teach it to someone else.

Other organizations will hand out what amounts to a step-by-step guide to pitching mechanics. At least one prominent national organization has a guide based on scientific research, and they make the research available for the coaches to read if they so choose. Unfortunately, even if a coach chooses to read the material, there is no guarantee that he will understand it. The coach's interpretation further obscures the science behind the guidelines which are someone else's interpretation of the research. This model is better than most, but is clearly not ideal.

In a perfect pitching world, all pitching coaches would be well versed in biomechanics - a sports science that combines mechanical physics and human physiology.

Throwing a pitch is a pretty simple task - accelerate the baseball toward the catcher's mitt - and the human body is the incredibly complex machine that executes it. A large collection of levers (bones) and pullies (muscles and tendons) create a kinetic chain from the pitcher's feet to his finger tips.

Newton's laws of motion describe the movement and acceleration, and human physiology determines how the levers and pullies of the body work together. Used in tandem, they can help identify mechanical inefficiencies and injury risk factors.

Pitching coaches that gloss over these subjects or pay no attention to them are cheating their clients and potentially endangering them.  There are prominent coaches who teach things that are unquestionably inefficient and others who teach things that are physiologically reckless.

Coaches who are dedicated to their own continued education give their clients the best chance for success.

If you are serious about hiring a pitching coach, you should have some idea of what he will be teaching. You must educate yourself.

In the absence of knowledge, it becomes a question of trust.