There are a couple of recent comments that I'd like to pull up here to the big board:

#1 - A comment from Mr. JP Francoeur of JP Fitness

JP's comment stated the need for sufficient strength in order to maintain correct sequence patterns.

The following was part of my initial response response:

"I understand your position about strength deficit, but I still feel like mechanics/technique plays a role (maybe or maybe not specific to Jeff Francoeur). 
For example, weight distribution at the time of stride foot plant will effect how rotation takes place.

Flexibility may also be an issue.  Here is a question:  is it possible for a hitter to be too flexible across the 'serape' muscles of the torso?  Just like too much laxity in the shoulder joint opens the door to injury.  Torso flexibility may be great for golf, but not to the same extent for baseball due to time contraints."

Given a time constraint, as in baseball batting, I would imagine that an optimal load/stretch is a necessary part of the basic compromise between mutually exclusive ends of maximal bat speed and maximal swing quickness.

On top of that, I'd agree with JP in a case such as Francoeur that a possible plan of attack would be to focus on concentric strength in diagonal rotation patterns in order to improve swing quickness.  Assuming a player can 'get away with' more separation, it could be a good thing --- just have to make sure the swing is executed in the given time period.

I'll also mention again, if you have not checked out the JP Fitness Forum, it is worth a visit.


#2 - anonymous comment goes like this:

"I was wondering if you had an opinion on the benefits of a longer stride when batting."

In my personal experience measuring bat speed for myself and other players, I would say that the stride contributes about 10% to maximal bat velocity.  This is an example of what I mean:  Player A has 100 mph maximum bat speed using his stride.  Player A also achieved a maxmimum bat speed of 90 mph without using the stride.  This was what I generally saw with college and minor league level players.

I have to add there that those not experience taking swing without a stride had a bigger difference.  Similar to my comments on my biomechanics project.  This was mainly because they heavily relied on thier arms, dragging the bat, etc. to create bat speed.  Over time, they learned to use their body more efficiently to produce bat speed and quickness.

Research wise, the only number I can reference specifically is from a golf biomechanics study that quantified a 10% contribution from lateral movement/shift prior to launching the swing.

Baseball studies show weight bearing on the front foot to be greater than 100% of body weight at the time the stride foot lands, which suggests the need to get the weight shifted to the front leg.  Actual picking up of the foot is really a matter of preference, comfortability (ie. golfers have the same shift without the actual stride).

My word of caution about trying to create too much bat speed by way of the stride is this - while a biomechanics study on ground reaction forces in pitching did show a correlation between total ground forces produces and linear wrist velocity (speed of the throwing hand moving toward it's target at release), GRF that peaked too soon showed a negative correlation to the same wrist velocity. 

My interpretation of that is basically if you push (forcefull extension of back leg) too soon, then you're in troube.  Rather, you're looking for a controlled build up of momentum leading to forceful, late rotation as the stride foot begin to land.

Personally, I usually focus on reaching good athletic positions, instead of a set idea of stide length.  Especially with objective feedback, players tend to figure out which positions are good and not so good.