I'm Jaime Cevallos. I authored three books on the mechanics of the baseball swing.
Growing up, it was my dream to play professional baseball. The only problem was I couldn't hit. I sought help from books and coaches, but nothing helped. Then one day in college, while tinkering with my swing mechanics, I stumbled upon a change that actually worked, and in a single instant, I went from the worst hitter on my team to the best. No joke, I went from never hitting a home run in my life, to hitting them pretty regularly. This showed me that there is immense opportunity when it comes to making changes to your mechanics, and that you can make small, simple changes that can yield huge results.
After my improvement in college, I would soon after lose my swing and struggle again. This sent me on a journey of studying the swing obsessively for more than two decades. I finally discovered the secret to the swing - that great hitters develop "front arm dominant" mechanics. It works like this: The greatest pound for pound hitters developed their swings at a very young age, at a time when their back arms weren't strong enough to take over. This made them develop a unique, and extremely advantageous swing structure, and it essentially gave their body room to rotate through the hit, as opposed to getting stuck and running out of room which is what happens when the back arm overexerts. Therefore the hitters who learned to swing when their back arms weren't strong enough to dominate the movement were able to develop a front arm dominant swing. It's front arm dominance that is the essential trait of the greatest pound for pound hitters. That's why we see this correlation between greatest hitters and being dominant in their front arm.
Notice in the above picture the contrast in positioning at contact between a more back arm dominant hitter in Tony Gwynn (left) and a prime example of a front arm dominant hitter in Ken Griffey Jr. (right). Notice how disconnected Gwynn is, and how connected Griffey is. Although Gwynn had an amazing career, you'll more often see his positioning at contact in hitters who lack power.
The front arm dominant swing is a more free flowing movement compared to the machine-like swings of today's old school and new school methods. Begin looking out for the front arm dominant swing structure when watching other hitters and you'll see that even the greatest hitters in your league will tend to be more front arm dominant.
The truth is, anyone can be a power hitter. You just have to understand the right feeling through the swing. Let me show you the simple change you can make to your swing right now that will make all the difference.