Spine angle throughout the swing is very important.  The angle and position of the spine helps to put the body in the correct position to create an optimal bat path and create power. When talking about spine angle, we can discuss the angle of the spine in the Frontal plane or the sagittal plane.  The frontal plane would be the lean of the hitters upper body towards home plate from pitchers view. The Sagittal plane or side view is the amount a hitter leans forward towards the pitcher or away from the pitcher.  Both positions play a significant role in proper swing mechanics.  For this article, we will discuss the side view and how much lean back or forward a hitter has at contact.

For this article I am going to showcase 2 left handed hitters on the opposite end of the hitting spectrum.  First, Chris Davis, who has a lifetime batting average of .250 and is most known for his power.  He has led the league in homeruns twice and has a 162 game average of 38 homeruns.  However, he also has led the league in strikeouts the past 2 seasons with 208 and 219 respectively.  On the other end, we has Ichiro Suzuki, a 2 time batting champion with a lifetime batting average of .313.  Has never been a big power guy, averaging only 7 homeruns over 162 game season, he also has never struck out more than 86 times in a single season.  

Below are pictures of both guys at/just after contact. What this article focuses on is the blue line, the angle of the hitters spine in the saggital plane.

What do we notice?  Chris Davis is leaning back much more than Ichiro.  So, who is correct?  The answer is both of them.  For what their strengths are as hitters, they are doing what suits them the best.  

If we look at the yellow line, this represents the path of the bat moving through the hitting zone.  Generally, with proper mechanics, the bat path will be close to perpendicular to the angle of the hitters spine.  This means that the more angled the spine is, or leaned back, the more incline the bat path will have to it.  Vice versa, the more vertical the spine angle is, the flatter the bat path will be.  We never want the blue line (our spine) to be tilted forward

The average pitch in the major leagues comes in on a downward plane, depending on many different factors,  between 6-12 degrees.  As a hitter, our job is to meet the path of the pitch with the path of our bat.  This means that to have the best chance at making good contact, the hitter would want to be somewhere between this 6-12 degree upward path.

This is what Ichiro does.  His bat is on he path of the pitch for a long distance, resulting in more contact.  However, this path also limits how much he can drive the baseball.

On the other hand, Chris Davis, due to his more tilted back spine angle, is moving the bat through the hitting zone at a much more inclined path.  The problem with having a steeper incline is that the area that a hitter has to make good contact is reduced.  This results in increased strikeouts and mishit balls.  However, this also results in bigger power numbers meaning extra base hits go up.

In order to drive the baseball, a hitter must change this angle to be steeper (more inclined).  This picture below represents the difference in Nomar Garciapparas swing on a normal game speed pitch and a pitch he is trying to hit over the fence in a homerun derby. Many homeruns in the major leagues come as a result of swing launch angles of 20-40 degrees.

So what should you do?

I used these 2 hitters to show the opposite ends of the hitting spectrum.  Each player can be where the are because of their unique abilities.  Most hitters are not nearly as big and strong as Chris Davis.  Most hitters do not possess the speed and bat control that Ichiro does.  So, I believe that most hitters should fall somewhere in the middle.  I generally tell hitters that I want them close to having their head over their hip over their knee at contact, with a slight lean back.  This can give them the opportunity to stay of the path of the pitch and well as give them the ability to drive the baseball. 

If a hitter has been told to chop down on the ball, or their bat path is flat or down, usually they will have a torso that is leaning forward.  In this instance, I will give the hitter the cue to lean back, which in many cases will help them fix their bat path.  However, if a player is too far back, they need to learn how to get a more neutral spinal position to get their bat on the plane of the pitch for a longer time.