Thank you. Good summary.

I was forced to drop from 14's to 12's after back surgery a year ago and still haven't mastered the swing of such a light weight ball. Still fighting my having a forced swing with 12's. Have just started trying to move up to 13's the past couple of weeks. Based on initial results, I doubt I will be able to go back to 14's though, let alone 15's.

I enjoyed this post.  I don't know that it is necessary to change the layout of a ball based on weight.  Surface prep would probably go a lot further.

The author had to drop down to 14lb due to an injury.  That's completely understandable.  I did the same thing and have noticed similar results.  There is something to be said for pain free bowling.  But, what if there is tactical advantage?

Now, one thing I have learned from JustRico's book, is that perception is NOT always reality.  It's a shame USBC didn't read that before changing the ball drilling rules for no thumb bowlers.  That's another subject.

I would like to know the difference between a 15lb ball traveling at 15mph VS. a 14lb ball traveling at 16mph at the point of impact.  Mainly looking at the force created between the two.  I'll let someone else do the calculations.

While it is true that a 15lb will have more friction than a 14lb, was does that amount to on a 60 foot lane with a THS?  What would be interesting is to see a graph of the two overlapped.

There is a lot of physics at work.  I would imagine under the rights circumstances a 14lb ball could carry better than a 15lb or even a 16lbs.  But to know for sure would take more than just what we perceive to be happening.

Great discussion on this topic.

Regarding the physics, it does get a little complicated but at the risk of simplicity, here goes:

The momentum (p), created by the ball is dependent on the ball's mass (m) and its velocity (v). Momentum is calculated by the formula p= mv.

Comparing the 2 balls, it is important to understand that if the bowler does not apply
any force throughout the swing cycle, but instead, relies on pure gravity, then both
balls will essentially travel down the lane at the same speed. Frictional forces can, but not always, cause the heavier ball to travel a tad slower, but the heavier ball
will also have more momentum, due to its increased mass. So, if we plug in some numbers we can see that the heavier ball will generate more momentum:

p=mv  m=14# & v= 20ft/sec (an arbitrary velocity)
p= 14 x 20= 280 lb-ft/sec

p= mv  m= 15# & v= 20 ft/sec
p=15x20=300lb-ft/sec

However, in determining a ball's hitting power, several other factors must be considered. These include the ball's entry angle, revolutions created by the hand,
core design, pin, ball and kickback coefficients of restitution (their "springiness").
All of these factors are indeed, affected by ball weight when it come to maximizing pin action. Taken together, there is an optimum quantity for each of these factors that will maximize pin carry. The math gets very very detailed here and depending on how each of these numbers play out,  will determine which ball weight will maximize  carry.

Again, at the risk of simplicity, a bowler who can accelerate through their release and who has the longest "time" span between when their thumb releases and when their fingers do, will IN GENERAL, benefit by going to a somewhat lighter ball, if as a result, it creates increased entry angle. Power players will benefit most here.

On the other hand, for those who, by virtue of their release style cannot generate
more "revs" in this fashion, they will almost always benefit by going with a heavier ball.
I fall squarely into this category. I dropped from 16# to 15# a while back and there is no disputing the fact that I had better "carry" with the 16# ball. Age necessitated
the change but if it had not, I would still be throwing 16#.

15mph = 22.00 ft/sec
16mph = 23.46 ft/sec

15 lbs x 22.0 ft/sec = 330 lbs-ft/sec
14 lbs x 23.46 ft/sec = 328.4 lbs-ft/sec

Less than 0.5% difference.  So, if a person drops from 15lb to 14lb AND is able to increase their speed, what's the difference?

I know there is a lot more physics involved.  Revs, angle, friction.....but it is interesting.

I feel (or perceive) that light hits carry better with 14.  I agree with the author that I see more 7 pins.

I do agree about leaving more 7 pins. But for me, my light hits turn into 7-10's.   I have left more solid 8's than I did when i threw 15's

Biggest place added weight helps is on really long patterns like Badger.  I have less margin of error in my release when it comes to carry with my 15 than I would a 16.  More likely to leave an 8-10 or 5-7 if I hit up a bit, or circle the ball too much.