So what about those other two acronymns – BPF and COR? More about COP as well.
Hello Fastpitch friends.
If last night’s bulletin piqued your interest or even if it didn’t, here is some more information for you to digest.
COP or Center of Percussion was last night’s scientific terminology. Here is a little more about that.
So, if you choke up or shorten up as some coaches yell at batters, you are changing your hand position on the bat changes where the pivot point is, which therefore changes the position of the COP to one that corresponds to your new pivot point.
To find the COP on a bat, try this exercise. Hold the bat parallel to the ground in what would be your top hand (right hand for righties and left hand for lefties). Make sure you hold the bat in the same place that you would if you were actually going to bat with it now. It’s easier to feel the push if you hodl the bat with only one hand; a two-handed grip helps counteract the push in either direction. Just be sure to hold it with your top hand in its normal position, no closer to the handle knob than it would be if you were gripping with both hands when batting. Close your eyes so you can concentrate on the sensations you feel in your hand.
Have someone else throw a ball at the bat from a few inches away, starting at the end farthest from your hand and have them keep doing that all the while moving the point of contact closer to your hand. The harder they throw it, the better (as long as the thrower is able to control where on the bat they are throwing the ball). Notice how the bat feels in yourhand as the ball strikes it. The amount of vibration and “push” varies, depending on where the bat the ball is hit. Some may find it a little hard to distinguish between t he two feelings, but if you can, the COP is where you feel the smallest push on your hand.
A bat is essentially a long stick. When you hit a stick off center, two things happen. The entire stick wants to move straight backward and it also wants to rotate around its center. It’s this tendenc y to rotate that makes the bat’s handle push back on or pull our of your hands.
When the ball hits the bat’s COP, you don’t feel a push or pull as the bat tries to spin. It’s because when the bat spins, it pivots around one stationary point. When you hit a ball at the COP, the stationary point conincides with where your top hand is. So your hand feels no push one way or the other.
If you want to hit the ball a long way, this is important. Every time you hit a ball at a point that’s not the COP of your bat, some of the energy of your swing goes into moving the bat in your hands, not pushing the ball so that it moves away from you rather and faster. If less of the bat’s enegy goes into your hands, more of it can be given to the ball.
Aluminum bats and composite bats are a bit different from wooden bats but still have a COP. A good test of where the COP is on one of these bats consists of holding the bat with your top hand right up against the knob. While you do this one keep track of your best total of hits on the bat. Use a poly-core bal if you have one intead of a cork center ball (although a cork center bal will work). Try to bounce teh ball off the barrel end of the bat as many times as you can in without losing control of the bat and ball. As it bounces on the bat, notice where it hits when it feels good and where it hits when you feel a deadening sensation or vibration.
A final note: all bats, wooden, metal or composite have a tendency to rotate in the hands. Holding the bat properly and not deep in the palms eliminates some of the rotational forces on the bat when contact is made.
So what is BPF?
Long ago there were wooden bats and nothing else. Then metal arrived, then magnesiunm followed by ceramic, then it was 7641 aluminum, followed by CU-31, then titanium, scandium, composite and more. So much more and so much trampoline effect that the game became increasingly more dangerous. The powers above decided something had to be done. So, they came up with testing methods to record to the exit speeds of balls leaving bats. They first tested wooden bats so as to have a base by which to start from. Then they started testing all the bats that the manufacturers had already entered into the market. Then they moved on to testing bats that were soon to hit the market.
Any bat that had exit speeds in excess of 120% of what the exit speeds for wooden bats were deemed to be “banned bats,” To cause me to shake my head even further they ruled that wooden bats had to have a 2000 or 2004 ASA sticker or insignia on them. Really, I asked. All other bats are compared to wooden bats and can’t have a BPF (bat performance factor) of more than 120% above a wooden bat but wooden bats are illegal? They changed it and now wooden bats are legal.
The balls are another issue. Long ago all balls had cork centers or had some kapok wrapped around cork etc. They were hard when the games started but the more the ball got banged around the softer they became. In actuality they were really soft balls.
Then the ball manufacturers responded to the outcrys from the slow pitch world that balls got soft too fast and those guys could not longer hit bombs over the 300’ fences. So, the ball manufacturers came up with poly-core balls that maintained their hardness throughout the games and could be used in many games with the same results.
So we added high tech bats and high tech balls called Patriots and other missle type names because they flew out of parks like scuds or Patriots. High tech bats and high tech balls were and still are a formula for disaster. Thus we now have defensive face masks in the games. That’s a good thing as long as the bats and balls are so “hot.”
Balls can’t exceed .47 COR. The COR stands for Coefficient of Restitution. According to physics experts, Coefficient of Resitution is: the ratio of the relative velocity after impact to the relative velocity before the impact of two colliding bodies, equal to 1 for an elastic collision and 0 for an inelastic collision.
So what does than mean in terms of softballs. Here is a link to a website that can explain things in detail.
In a nutshell here is what it means in the baseball and softbal world. If a ball is traveling 60 mph when it collides with a solid object such as a solid wall, then rebounds off that wall, when the ball leaves the wall it can’t be traveling more than 47% of 60 mph. If it travels faster than that it’s not a legal softball anymore. There was a time when we were using balls that had a COR of .50. In other words those balls would be going 30 mph when measured after rebounding.
The rules say the balls can’t exceed .47 COR. But that does not mean that a ball tests as high as .47. Many of the balls used by Wisconsin high school teams are actually closer to .44 when they are out of the box and after being hit around lose COR.
That’s it in simple terms. Poly Core balls stay hard and retain COR that was present out of the box at a higher level than cork center balls. That should answer your question as to why college players hit so many more home runs than high school players. There is more too it than just technique and it has to do with the core of the ball that is being used.
For kicks try this test. Get a Dudley 12LND ball that the WIAA uses in the state tournament. Then get a ball such as a Dudley Thunder Heat. Take both to a concrete slab like a sidewalk. Throw the cork center ball down onto the concrete as hard as you can and notice how high it bounces back up. Then take the poly-core ball and do the same thing. Listen to the differenc e and then notice the difference.
A number of years ago (it was back in the 1990s) our team played a road game where the home team was using a poly- core ball. The balls of course were white ones. We played the game and several shots were hit during the game. After the game was over I chatted with the opposing coach and warned the coach that somebody was going to get hurt if they continued to use those balls. A game or two later on their schedule a player did indeed get drilled by a line drive with those balls and the injured player lost teeth and had facial cuts. She played for the coach that was using those balls. Defensive masks were not even in the mix in the 1990s.
I do well remember watching a collegiate pitcher for UW-Green Bay wearing a batting helmet with a football face mask attached because she had been hit in the face while pitching in high school. Defensive face masks are a great addition to our game.
More of my thoughts on defensive face masks and who should use them will be covered in the next bulletin. It will give you something to think about.
Have a fastpitch day and ---
Keep it Rising!
Bob
