Baseball Bat – Ball Collision Using Blast, Diamond Kinetics, and Hit Trax – How Can We Use Data for Bat Fittings?

About a year ago I started to get interested in bat/ball collision and what perfect impact would look like and how we could tell as baseball players, instructors, and in analyzing data.  I reached out to Dr. Alan Nathan who is considered the leader in the baseball field.  We went back and forth and he settled on basically saying I should dig into this more if I have access to real life data.  So I did…

There is a lot of scientific information and formulas that he and others have spent a lot of time on but it gets very confusing and data overload.  I wanted to dig into this in a real world way with Blast, Diamond Kinetics, and Hit Trax.  I collected data and I had others send me verified data that is trusted.  All the work is on metal bats, bbcor, -3 (we can get into wood bats another time but I found that there isn’t much of a difference).  The goal was to come up with some ratios and metrics that could be used to verify solid contact.  Lets get into the data and remember I am keeping this straight forward and simple.  You can get lost digging into this stuff.


Base Information

Calculations used from Dr Nathan and can be dove into here:

Exit velo = (Bat Speed x 1.2) + (Pitch Speed x 0.2)

So a bat speed from Blast of 61.7 mph and a pitch speed of 68 mph should equal an optimal exit velo of 87.64 mph.  Thats (61.7×1.2)+(68×0.2)= 83.64 or (74.04) + (13.6) = 87.64.  This is ignoring launch angle which is a whole other discussion and factor that changes everything.  We are only worried about pure max exit velo based on bat speed and pitch speed.

What is Smash Factor – Golf

You should probably understand smash factor as well.  Golf again was ahead of baseball.  If you ever did a driver/shaft fitting, you know that the smash factor is one of the most important numbers.  Also keep in mind that a golf ball sits on a tee vs a pitch coming in at 90 mph and in different locations with different movements.  In golf we can discuss absolute optimal numbers.  In baseball these rarely happen and when they do we hit home runs.

Here is a definition and link.

Smash factor is a golf term that might sound intimidating, but to me it is the most important metric for ball striking. It is simply defined as the ball speed divided by clubhead speed. I like to think of it as how efficiently you are hitting the golf ball. For example, if your swing speed was 100mph and your ball speed was 135mph, then your smash factor would be 1.35.

Every player wants to know how to hit a golf ball farther. It is all we read about and hear about from the mainstream golf media. Essentially you have two options:

  1. Swing faster
  2. Increase your strike efficiency



The data random bat/ball speeds collected.  All of these were the best contact and best outcomes of a hitters session based on exit velo, not distance.  Although those do line up for some (ideally they always would).  It would  include Blast lining up with Hit Trax on that swing.  We collected:

Bat Speed – Hand Speed – Exit Velo – Launch Angle – Distance – Pitch Speed

Bat Bat Speed Hand Speed Exit Velo Launch Distance Pitch Speed
metal 61.7 21.4 82.9 22 267 68
metal 65.4 19.3 82.1 17 250 33
metal 60.3 18.9 76.9 11 136 39
metal 70.2 24.7 97 19 300 36
metal 73.1 23.1 91.1 20 299 38
metal 68.1 23.1 88.1 10 195 36


Data Breakdown

  • Bat/Exit = is basically the smash factor in golf.   This is the ratio that would be the easiest to determine optimal contact.  It is bat speed divided by exit velo.
  • 1.2 0.2 Exp = is just what the optimal exit velo should be based on bat speed and pitch speed.
  • Act – Exp = is Actual exit velo minus expected optimal velo.
  • Opt Bat/Exit = Optimal ratios
Bat Bat Speed Hand Speed Exit Velo Launch Distance Pitch Speed Bat/Exit 1.2 0.2 Exp Act – Exp Opt Bat/Exit
metal 61.7 21.4 82.9 22 267 68 1.34 87.64 -4.74 1.420
metal 65.4 19.3 82.1 17 250 33 1.26 85.08 -2.98 1.301
metal 60.3 18.9 76.9 11 136 39 1.28 80.16 -3.26 1.329
metal 70.2 24.7 97 19 300 36 1.38 91.44 5.56 1.303
metal 73.1 23.1 91.1 20 299 38 1.25 95.32 -4.22 1.304
metal 68.1 23.1 88.1 10 195 36 1.29 88.92 -0.82 1.306


Analyzing this data made it clear that the ratio we should be looking at is Bat/Exit and comparing that to Opt Bat/Exit.  The challenge here is that the Opt Bat/Exit changes based on bat speed and pitch speed.  These ratios get bigger as those go up.  Here is a chart to explain.

Bat Speed Pitch Speed 1.2 0.2 Exp Opt Bat/Exit
62 40 82.4 1.329
65 40 86 1.323
68 40 89.6 1.318
72 40 94.4 1.311
76 40 99.2 1.305
62 70 88.4 1.426
65 70 92 1.415
68 70 95.6 1.406
72 70 100.4 1.394
76 70 105.2 1.384
62 80 90.4 1.458
65 80 94 1.446
68 80 97.6 1.435
72 80 102.4 1.422
76 80 107.2 1.411
62 90 92.4 1.490
65 90 96 1.477
68 90 99.6 1.465
72 90 104.4 1.450
76 90 109.2 1.437
62 95 93.4 1.506
65 95 97 1.492
68 95 100.6 1.479
72 95 105.4 1.464
76 95 110.2 1.450

This clearly shows that when speeds increase, optimal contact ratios increase.  We simply cant use the same ratio for tee work as flips as machine pitches.  We also have to factor in the players swing speed.  I imagine we can take thousands of swings and categorize them in contact as A+, A, B, C, D F and then work from there to learn how to equate expected performance based on players average bat speed and pitchers average pitch speed per pitch (we are only discussing fastballs here, curves change these ratios).

What is also interesting is as swing speed increases, Opt Bat/Exit decreases.  A slower bat speed at the same pitch speed should actually be more optimal vs a faster bat speed.  For example:

90 mph pitch.  62 mph bat speed has the ability to hit a ball 92.4 mph which is a 1.490 ratio vs a 76 mph bat speed, 109.2 mph exit, and 1.437 ratio.


So what is an optimal swing and how do we know?  We need both bat speed and exit velo then we look at these formulas to determine where that bat speed should fall and then we calculate the ratio.  Remember, the ratio is simply exit velo divided by bat speed.  But these changes as each speed changes.  At the MLB level, you would like to see a ratio in the 1.425-1.475 range vs 90+ pitching.  Do not use this ratio for BP.  A ratio of 1.3 or more would be ideal for BP.


Side Note

I have seen some exit velos that do not correlate with the swing speed. I don’t know why this happens but these don’t translate into real in game results.  This will be a learning experience so what I post today may change when more data is collected.

I also want to test exit velos off tees but I never have. I’d like to gather a bunch of mlb results with blast connected.

Swingweight Changes and Performance in Golf Clubs and How it Relates to Baseball

This is a continuation on my last post about bat balance points and swingweights.  What nice about this post is that most of the work has been done on the golf side.  Lets look at it.  I found this website and this club fitter experimented with different swingweights and tested with 6 players.  His findings are interesting yet expected.

It should be noted that DO to D3 or any change in 3 steps of swingweight is adding or subtracting 6 grams or 0.2 oz.  Each swingweight change (DO being the lightest) is 2 grams or 0.07 oz.  (almost nothing) yet each golfer immediately noticed the change in weight.  Now a bat is shorter and heavier so the addition or subtraction in weight needs to be more.  I found that 3 oz showed a very noticeable change.  The information is in the post link below.


The data:



This is very interesting because golf will track launch angle, ball speed, spin, carry, attack angle, path, offline, and smash factor.  All of these should look familiar to the baseball guy and statcast.  It should be noted that golf is 10-15 years ahead of baseball in this regard.

Lets break down each player and only look at speeds and contact.  This is because in golf there is more than launch angle and ball speed because spin rate plays into carry but after the ball hits the ground, the less spin, the more roll.  So golfers look at total distance vs baseball looks at total carry.

  • Player 1
    • As weight increases, Club head speed decreases.
    • Ball speed decreases slightly.
    • Smash factor stays consistent (quality of contact where 1.5 is the best)
    • Total distance decreases slightly but control increases.
  • Player 2
    • As weight increases, Club head speed decreases.
    • Ball speed decreases substantially.
    • Smash factor stays consistent.
    • Total distance decreases substantially and control decreases.
  • Player 3
    • As weight increases, Club head speed decreases slightly.
    • Ball speed decreases substantially.
    • Smash factor stays consistent.
    • Total distance decreases slightly and control stays consistent.
  • Player 4
    • As weight increases, Club head speed decreases.
    • Ball speed decreases substantially.
    • Smash factor stays consistent but does increase in the middle swingweights.
    • Total distance decreases substantially and control decreases.
  • Player 5
    • As weight increases, Club head stays consistent.
    • Ball speed increases substantially.
    • Smash factor increases
    • Total distance increases substantially and control increases.
  • Player 6
    • As weight increases, Club head speed decreases slightly.
    • Ball speed stays consistent.
    • Smash factor stays consistent.
    • Total distance stays consistent and control stays consistent.


Player 5 gained the most from increasing swingweight.  This allowed him to hit the ball 25 yards further and more in the center of the fairway.  But no other player saw an increase in distance or control.  The next step to this test would be to then take those players and decrease the swingweights lower than D0 and see if they gain an advantage going lighter.

Why I said that the results were to be expected earlier in this post is because everyone is unique and swing differently.  This means that there is no one magic club or bat for everyone.  A lot more time needs to be put into the idea of bat fitting and we need to look at it like golf club fitters do.

I learned that I can change the swingweight of a baseball bat.  I can notice a difference that makes the bat feel lighter and quicker.  Now I need to get to the point where I can test this and hit balls to get swing speed and exit velo numbers and compare.  We need to know whats best for each hitter.  End loaded, balanced, handle loaded, length, and overall weight.


Baseball Bat Swingweight and Balance Points – Why Can You Swing a Metal Bat Faster Than Wood?

I have always been interested in the concept of baseball bat fitting, especially coming from the golf world where club fittings are a large part of the new golf club buying experience.  Not only do you have to deal with different manufactures, but each manufacturer has different club heads that can be set up in hundreds of different combinations with weights.  Then the most important part is the shaft and there are hundreds of shafts to choose from.  Each shaft has different weights, weight distribution, kick points, and flex.  But then the even more serious golfers get into shaft length and tipping shafts which is making a shaft stiffer than it should be on spec because of where you trim it.

Here is a chart on what can change a swingweight.  Remember that a small change in swingweight feels very different.

I remember reading about Jack Nicklaus counter balancing his golf clubs in the 1970s by using pennies in his grips.  This changed the balance point of the club or the swingweight.  Think of swingweight as the balance of the club.  Swingweight is the relationship between the amount of weight at the bottom two-thirds of the club vs the top one third.  This translates to how a club feels vs how heavy a club is.  Now how does this apply to baseball bats?

The quick answer is I don’t know yet but here is why I am interested, and these are my findings so far…

We all hear of bats being end loaded or balanced.  A 243 or i13 with a large barrel will be end loaded and feel heavier than an M110 or 318.  This is usually because the barrels are smaller and/or because the handles are thicker (counterbalance).  But when you choose your bat, do you even pay attention to this or do you just pick what looks appealing to you and what feels best?  I think 2019 is the year where baseball bat fitting becomes a thing.  A player should also consider length and cupping options.  As a general rule, bat manufactures are confined to density requirements set by the MLB and length to weight ratios of -3.  But nobody ever discusses making bats heavier by counterbalancing them or lowering swingweights like golf clubs.

I personally use wood bats and on a test,  I found that every wood bat had the same general balance point whether it was an end loaded or balanced bat.  But metal bbcor bats have a different balance point that is closer to the knob.  This makes even heavier bats feel lighter.  And to push it further, balanced metal bat models have the balance point shifted a lot closer to the knob.  In the picture below the yellow tape represents the balance point of each bat.  Each bat is 33.5” except for the last balanced one-piece voodoo bat which is 34” (I don’t have many metal bats to compare).


Why am I researching this?

One day I tested swing speeds and exit velocities with metal vs wood bats and the findings confused me.  I even reached out to Driveline Baseball to see if they have experienced the same thing or had any answers.  They agree with my thoughts but didn’t know why.  I found that even though the metal bats felt and were heavier and even more end loaded, I swung them faster and I felt quicker to the ball than with the wood bats.  Keep in mind that the metal bats should be -3 but the are actually 33.5/32.8 and 34/32.5 so -0.7 and -1.5 respectively.  A person would assume that a heavier bat would be swung slower, not faster.  So, what is going on here?

Bat Speed Avg Bat Speed Max Hand Speed Avg Hand Speed Max Attack Avg Attack Max Power Avg Power Max
33.5/31 Wood 67.3 70.8 20.4 22.7 15 20 3.05 3.42
33.5/31.5 Wood 67.8 70.5 21.2 21.9 14 19 3.14 3.5
33.5/32.8 Metal 68.5 71.8 21.8 23.3 17 21 3.24 3.61
34/32.5 Metal 69.9 72.3 22.1 23.2 14 20 3.45 3.72


I think it has to do with balance points and swingweight.  So how can we change the swingweight on a bat?

  • Cup the end
    • Cupping removes 0.3 to 0.8 oz at the end of the bat.  This moves the balance point closer to the knob vs the barrel.  We will learn that 0.3-0.8 oz isn’t that much in terms of feel for swingweight but for overall weight this decrease helps meet density.
  • Thicker handle
    • Thicker handles work by balancing the bat.  This is a good way to have a bat feel lighter even if its the same weight.  You would have to compare an exact model and weight bat to its match with only a thicker handle.  This will also increase the overall weight of the bat.
  • Smaller or larger barrel
    • Smaller barrels will move the balance point to the knob and larger to the end.
  • Length of barrel
    • A barrel can be long or short.  This depends on the taper of the bat from the knob to the barrel.  Short tapers will have longer barrels and more end loaded bats.
  • Size of knob
    • I haven’t heard much about this but the size of the knob can counterbalance a heavier barrel.  The issue is that you cant make a knob heavy enough to really impact the swingweight (or can you).
  • Use lead tape to test
    • Golfers and tennis players use lead tape to change swingweight and overall weights of their equipment.  Baseball players cant do this but with some testing, maybe we can develop new bat models to better fit certain players.

This leads me to a test I did with adding weight to bats to change the balance point.  I wanted to see how much weight and where the weight needed to be applied to make a difference.

The Victus bat below is a BO23 model.  This is a large and long barrel with a thicker handle and large standard knob.  This creates the largest barreled bat with the most balance that I have used.  The yellow tape and line – marks indicate the balance points of the bat.

From Right to Left

Far Right – This is the standard normal balance point

Middle – This is the new balance point when 1.4 oz is used and placed half way between the knob and the standard balance point.  This was 11″ from the knob.

Left – This is the new balance point when 1.4 oz was added to the knob.



Next we have 1.9 oz with the same locations.

From Right to Left (middle group of tape)

Far Right – This is the standard normal balance point

Middle – This is the new balance point when 1.9 oz is used and placed half way between the knob and the standard balance point.  This is very slightly more towards the knob vs the 1.4 oz weight.

Left – This is the new balance point when 1.9 oz was added to the knob.   This is also very slightly changed towards the knob vs the 1.4 oz weight.

This shows that the difference of 1.4 or 1.9 oz is not that big of a change.

Next we should look at the bottom row of tape in the picture (above, same picture).  This row represents 3.3 oz which is using both weights at the same time.

From Right to Left (we know the standard balance point)

Right – This is the new balance point when 3.3 oz is used.  You can see that it shifts the balance point a lot more and is in between the middle and knob locations on the 1.9 oz weight.

Left – This is the new balance point when 3.3 oz was added to the knob.  This is a large shift and dramatically changes the swingweight and feel of the bat.



I haven’t set up a demo to be able to swing and test bat speeds with the weights installed.  I need to figure out how to do this, especially because I will need to add up to 2-3 oz.  What I can say is that the changes in the balance points all made a difference but the last one where 3.3 oz was added to the knob made a 31 oz bat feel like a kids 25 oz bat.  This is happening while you are still increasing the overall weight of the bat from 31 to 34.3 oz.  This makes me very interested to see how this will effect bat speed and exit velo.

Maple vs Ash Wood Bat Performance

I have been curious about ash v maple and its performance.  There have been a limited amount of studies done and maybe one 1 – 2 in a lab but the results didn’t show anything to consider.  I dont have access to a lab but I do have access to Hit Trax, Blast, Diamond Kinetics, and an MLB hitter who is VERY consistent.  The key here is the hitter being consistent and being able to hit a ball with the same swing and same power and same location over and over.

This study is not perfect because its still based on the human element but its something to look at.

  • Bats were weighed and identical models and manufactures
  • Flips were consistent
  • Swings were consistent
  • Each hit was a line drive in the same location
  • I threw out a couple outliers from either bad flips or a bad swing



What we found is that performance is the same.  The hitter actually went through the minors and early MLB year with ash and likes the feel of ash.  He thinks it feels more like it flexes and whips through the zone.  It may be a mental thing where a hitter would want to use one over the other.  There are some things to consider.

  • Studies have shown that the sweet spot on ash is a little larger (although I heard a very respected bat rep state that this isn’t true).
  • Ash doesn’t sting as much as maple on mishits.  I assume because it flexes.  This is a reason why some guys go to ash early and late in the year when the weather is cold.
  • Ash doesn’t have density requirements.  A player can get a bat that would be LDM-X or LDM in ash and it wouldn’t be an issue.  This is for guys who want larger barrel models like i13 and 243 in -3 ratios.
  • Ash is getting harder to source for manufactures.  Or I should say quality ash.


I look forward to looking into this more.