June 15, 2019 | @BatDigest
We surveyed over 1200 actual baseball players about their bat size to build a crowd sourced bat size chart.
The data we captured was much more interesting than we originally thought.
And oh so much more….see below for your self.
We also learned that determining factors like height, weight, skill and strength are NOT how player’s ultimately decide their at size. Instead, the number one factor in determining bat size is AGE. Not a single variable like weight, height, strength or skill was predictive or significant in choosing a bat that players were happy with.
Of each of those four variables (strength, weight, height and skill), strength was the most predictive although it still had a very weak correlation to bat weight or length. On average, it explained less than 20% of the variation in bat weight among players in a given age. Height, weight and skill all had next to no correlation at all. Height, oddly enough, had a negative correlation in some instances.
In other words, most players, likely due to the fact that they play on a team, swing about the same sized bat that the team does. And, since they are all the same age, swing about the same sized bat.
In other words, we suggest that any bat size chart using a height/weight structure to determine the right bat size is, to put it frankly, just plain wrong.
For starters, we measured the most popular bat sizes by age. This includes the bat size, drop and frequency (% of use). As an example, the most popular bat for a 9 year old is 28/18 of which 26.6% of player use. The 2nd most popular 9 year old bat is a 29/19 of which 24.5% use.
|Age||1st Most Popular Bat Size (% Use)||2nd Most Popular Bat Size (% Use)||See Chart|
|6||26/14 (.300)||28/16 (.200)|
|7||27/17 (.242)||28/18 (.152)||7 – Chart|
|8||28/18 (.230)||29/19 (.148)||8 – Chart|
|9||28/18 (.266)||29/19 (.245)||9 – Chart|
|10||29/19 (.331)||30/20 (.254)||10 – Chart|
|11||30/20 (.298)||31/21 (.119)||11 – Chart|
|12||30/20 (.173)||31/21 (.150)||12 – Chart|
|13*||31/26 (.200)||32/27 (.143)||13 – Non BBCOR|
|13||32/29 (.373)||31/28 (.373)||13 – BBCOR|
|14||32/29 (.430)||33/30 (.278)||14 – BBCOR|
|15||32/29 (.392)||33/30 (.266)||15 – BBCOR|
|16||33/30 (.446)||32/29 (.323)||16 – BBCOR|
|17||33/30 (.450)||32/29 or 34/30 (.200)||17 – BBCOR|
We took each of our 1200+ data points and dissected them into age. We then build alluvial charts (more on that in a second) showing how player characteristics like height, weight, skill and strength matched up with bat size and bat weight.
As well, we took the most common bats of each age and measured those against how players felt about their bat. As in, is your 31/21 too heavy or too light or just right?
Alluvial charts are flow diagrams built to better visualize the flow of attributes from one to another. In our bat size chart alluvial diagrams we pit the length or the weight of bat up against different characteristics within an age class.
Our visualization of bat size data by age is useful in a few ways. First, it allows us to quickly observe how different attributes affect bat sizes. For example, do overly strong kids always tend to prefer bigger bats. Or, do tall kids have a tendancy for the same types of bats as shorter kids. Maybe you’d like measure if players who are particularly skilled (or at least claim to be) are more likely to use a drop 8 or drop 10 as an 11 year old. The list goes on.
For each alluvial chart we do give some initial observations. But, our experience with them to date is that we notice something new every time we look.
We used RawGraphs to generate much of the structure and then some animation software to up the clarity.
We also use circle packing charts made, initially at least, with RawGraphs. These charts are simple enough. The size of the circle indicates the popularity of the bat. These sizes are in relation to the other bat sizes on the chart. Colors represent the likelihood hitters thought the bat was heavy or light.
We found, generally, most ages were pretty happy with a number of bat sizes. Some were comfortable with pretty much every one. Others had a few real losers of the group.
Although Circle Packing bat charts won’t quite narrow down the exact right size you or your player needs, it does give an accurate feel for what the age group tends to prefer and if there are any real bats sizes to avoid.
We asked 100 parents of 7 year old players about the right size bat for their player. The alluvial diagram below documents their feel based on the player’s metrics of height, weight, strength and skill level in relation to his peers.
There is too much information observed in the chart to comment on here. Each time we look at it we notice something different. Of the major things, we find that the average 7 year old uses a 17 ounce bat with a near 50/50 split on either a 27 or 28-inch. There are more 26-inch bats in the 7u space than 29-inches but not by much. Kids with an average height tend towards a 18 ounce bat as much as they do a 16 ounce bat but the majority is in between that at 17 ounces. Only very good players tend towards the 29/19’s.
There is also a sizable range in weights (from 13 to 19 ounces).
The right sized bat for a 7 year old player appears to circle around the 27/17. On average, most are also happy with the 28/18 and the 26/16. For some reason, maybe due to the model that is offered in that size, the 28/17 rates out a bit too heavy.
Average players, with average physical metrics should do alright with a 27/17. But, clearly, a mode of the 26.5/16.5 lends us to suggest a 26/16 as the second most likely fit. Note, too, that 13 ounce bats are mostly found in the T Ball space. If your 7U player is seeing kid or coach pitch do know their T Ball bat won’t do that well.
We surveyed over 200 8 year old baseball players bat size choices. We aggregated that data into a chart which foucsed on skill level, player strength, height and weight compared to their peers. The results for the 8 year olds are found in this bat size diagram.
The most common bat size for 8 year olds is a 28-inch and 18 ounce baseball bat. There are more 29-inch bats than 27-inch bats in the 8U space but there even more 19 ounce bats than there are 17 ounce bats. This is likely due to the fact many use a drop 11 in a 30 inch (upping the number of 19 ounce bats in 8 year olds hands).
Of some interest, players whose parents consider them short tended to avoid 18 ounce bats in the 8 year old space. They either swing a 17 or 19 ounce. Whereas tall players preferred 18 ounce.
Like we see in other age categories, very tall players tend to use lighter bats. We can’t explain why this is true across almost all of the data we collected. Possibly, tall kids parents don’t see the need for a longer bat. Or, maybe, overly tall kids at the age of 8 tend to be rather weak and uncoordinated and, therefore, prefer a shorter bat. In any event, the surveys we received from real players show very tall players tended towards the lighter end of the 8 year old bat spectrum.
In short, their are a ton of bat options for 8 year olds. To be safe, the 28/18 appears the most common choice among almost any type of attribute. If the player is particularly strong or skilled than a 29/19 might be in the mix. But, if you want bat speed then the 28/17 might be a home run, so to speak.
More commentary on the best and right bats for 8 year olds can be found on our best bat for 8 year olds page.
There is a remarkably wide range of baseball bat sizes for 9 year olds. As well, there does not appear to be any particular theme other than a general coalescence around the 29/19 and 28/18 sized bats. But, there are at least a few swinging a 30/20 and even fewer in the 31/21 range. We found that, for most, the 30/20 is too heavy a bat and players rated it too heavy for the 9U market.
We do notice that excellent 9 year old players tend towards the 20 ounce baseball bat and that weak players avoid anything more than an 18 ounce bat. Struggling players don’t swing anything over a 29-inch and only the strong and very strong consider anything over a 20-ounce bat.
8 year old players with average weight split pretty evenly across the 18, 19 and 20 ounce bat weight but tend to prefer the 29 and 28-inch over the 30. Meaning, if anything else, there are at least a few 29-inch drop 9 users out there.
20-ounce bats for 9 year olds tended to be too heavy. Some liked it, but most rated it as too heavy a stick for their age class. We’d recommend, if you are an excellent or big player to keep the bat size in the 29/19 range and stay away from 20-ounce bats until you’re 10. You can find more commentary on this chart as well as recommendations for 9 year olds bat choices on our best bat for 9 year olds page.
We surveyed 200 parents of players that are 10 years old about their bat size choices. The results are diagrammed in the following bat size chart.
For 10 year olds, the most common bat lengths, far and away when compared to other young age categories, are the 29 and 30 inch drop 10 sticks. But, unlike other younger players, every category of bat size for 10 year olds were generally happy with their bat size.
As we observe in other age specific bat charts, very tall players tend to avoid heavier bats. In fact, they tend towards lighter and shorter bats more averaged sized kids in their age group. We aren’t quite sure why this is, frankly. It could be due to the fact they don’t need as much length as shorter kids so aren’t worried about bat reach. Or, possibly, overly tall kids are not as coordinated and therefore need as small of bats as they can find.
There are a few strong and very strong kids who swing a 21-ounce bat as a 10 year old. But, we did not find any who were swinging a 32-inch bat. Meaning, obviously, at least a couple of the more advanced and bigger kids used a 30/21 drop 9. If you want to be safe stay with a 29/19 or 30/20.
We dissect this chart a bit more, and have specific suggestions for bat models, in our best bats for 10 year old page.
Over 200 parents of players with 11 year olds answered our bat size chart survey. We asked about the players height, weight, skill level and strength in relation to their peers. Like in all other categories, parents tended to believe their child was above average skill, shorter than everyone else and stronger than most. Granted, our site may offer some selection bias as only those with above average skill tend to care about their bats—and would find themselves on our site.
The perception that our children are generally shorter than they really are is a common theme in all these bat size charts. That false notion persisted for the 11-year old group of bat size chart surveys too.
We learn at least a few interesting things from the 11-year old bat chart survey data. In particular, the 30-inch and 20-ounce bat is a runaway favorite. But, in terms of a particular trait that drives to a bat size we found no overwhelming evidence. Players of all sorts and sizes swing bats from a 29/19 to a 31/21 pretty regularly.
As well, much like the 10 year old group, players are generally happy with their bat. Although a guess, we feel it a good assumption that 11 year old players have played enough baseball to know which bat fits them well. So, even those who liked a drop 5 31/26 are just as happy as the 29/19 players.
Strong 11 year old players tended towards the 30-inch as much as they liked the 31-inch. Very strong players were all over the 31-inch and made up a good chunk of the 22 ounce hitters too. The very tall, as we’ve seen in nearly every young bat size chart, still tend towards shorter and lighter bats. More 11 year olds swing a 23-ounce bat than an 18 ounce bat. We found only a couple parents who considered their player excellent that swing a 29-inch, but even fewer of them swing a 32-inch. Almost no parents who took the survey think their child is struggling, but those that did make a disproportionate amount of the 28-inch bats that are swung by 11 year olds.
We have more commentary on the bat tendencies of 11 year olds on our best bat for 11 year old page.
The bat size chart for the 12 year old is the most complicated by far. The range of normal bat sizes is as big as the range in 12 year old baseball body types. On average, bats range a good 9 ounces different and no single bat weight has more than 15% of the normal market. It is a marked contract to, say, the 17 year old population that really coalesces around just a few different bats.
Although there is no clear winner, the two most common bat sizes for 12 year olds are a 30/20 and a 31/21. But, there are more other sizes than those two combined. There are plenty of happy 32/22, 30/22, 31/23 and 32/24 12 year old hitters.
In terms of the alluvial chart there is so much to observe. Very good players, which make up the bulk of the skill section, swing all types of bats. Very strong players area also split evenly from 21 to 27-ounce bats. Heavy kids tend to stay with 30, 31 and 32 while the average weight section fills up the vast majority of the 29-inch bat section. Weak kids swing lighter bats (no surprise) but, again, very tall kids swing shorter bats (no idea why that keeps being the trend).
The things to notice feel endless.
In fact, there are plenty of drop 5 30, 31 and 32-inch players. Although the average for the drop 5 space is claims the bats are a little too heavy—there were several who believed the bat’s weights were right on the money.
We discuss more details of the chart with specific bat suggestions in our best bat for 12 year old section. But, in terms of the right bat size, we suggest a 12 year old go to a 31/21 if they have no idea. If they are an above average skill kid then a drop 8 in a 31/23 or 32/24 might make a ton of sense too.
In truth, though, most 13 year old players go to a BBCOR standards. Meaing, they are required to swing a drop 3. Some believe that it makes sense to gradually work up to that and attempt to get into a drop 5 ASAP so the jump to high school ball and a drop 3 isn’t too painful. That is reasonable thinking and we support the idea. That said, a 12 year old player who can’t hit the ball because his bat is too heavy often doesn’t end up playing high school baseball anyways. So, sure, a drop 5 makes sense—but only if they can still hit with it.
Based on the data we collected, about 1/3 of all 13 year olds still play in non BBCOR leagues. Our data collected about 100 of these individuals and, as you can see in the charts above, the bats tend to run a little light for most. But, there are plenty still finding right sized fit. We’d suggest, at 13, you look for a drop 5 in a 32. But, based on your skill level, height, weight and strength the below might be more directional.
There is plenty to notice in the 13 Year Old bat sizing space. Almost no players are still using a 29-inch. Very tall players continue to swing shorter bats than their average sized peers. Excellent players swing a 31-inch way more than 32-inch and way more often than their ‘average skill’ peers who tend to swing a 32-inch more often. Bat weight options are well spread out across a number of sizes but the most common is a 26-ounce.
In terms of frequency, there is a huge range of bat sizes in the non BBCOR 13 year old bat space.
Turns out, most of the hitters in the NON BBCOR 13 Year old baseball space think their bat is too light. Those swinging a 30/20 still, a huge portion, will be suprrised when they have to jump to a drop 3 next year. Only the bigger drop 8′ s as well as the drop 5’s appear too appease the growing muscles of 13 year old baseball players.
We do have an article that discusses bat model specifics in the 13 year old space here. But, if you want a general recommendation on size we stay stick with nothing lighter than a drop 8 and shoot for a 32 inch too. A 32/27 is a monster bat and might feel like a big boy bat to begin the year. But, as our data shows, most 32/27 hitters are pretty happy with their bat size—and staying with the bat size that 11 and 12 year olds prefer just doesn’t pack the kind of punch you want to see on a 13 year old ball field.
Entering the BBCOR bat world calms down the chart lines significantly. Mostly because the BBCOR world only uses drop threes. That is, BBCOR bats come only come in a 34, 33, 32, 31, 30 and 29-inch options. (Granted, there are a few companies that use a 32.5 and 33.5 model as well). Those 6 limited sizing options make the choices easier.
Note, for this data we removed wood bats which, we realize, are BBCOR approved. We also removed the 32.5 and 33.5 length options although we did have them in our survey. There were too few 32.5 and 33.5 responses to make the data meaningful so we removed them and just show you the whole numbers, as it were, below.
We are most surprised at how few 13 year old BBCOR players go for the 29/26. Granted, there are only a few companies that offer as much. But, considering many of the non BBCOR counterparts we document above prefer a 23 or 24 ounce bat you’d think more would be excited for a 26-ounce in BBCOR. But, that short 29-inch barrel clearly drives a lot to look to the 30-inch.
That said, we are also surprised to see that most 13 year old BBCOR players swing a 31-inch or 32-inch players than 30-inch players. In fact, about just as many use a 33-inch BBCOR than a 30-inch. At 13, that surprises us. As well, just as many 13 year olds are using 31/28 as they area 32/29 is surprising.
For the 13 year old BBCOR player it appears most have found the bat that suits them well. Even though there are several 33/30 hitters they did rate their bat as feeling it was the right weight for them. This makes it hard to recommend a particular size for a BBCOR bat and a 13 year old. The fact the 31 and 32-inch have the same dominant frequency makes us stay in that realm. If you’re aren’t quite sure which bat to get then we’d say lean towards to the 32-inch so it might last you through your 14 year season too.
In terms of a the best BBCOR bat for you we have an entire article dedicated to that conversation.
The 14 year old BBCOR bat size chart is spread equally across the 31, 32 and 33-inch space with slight edge to the 32-inch BBCOR bat. Like our other ages and categories, there are few specific traits that really determine the type of bat they should swing. For example, Strong players are just as likely to swing a 29-ounce bat as they are a 30-ounce bat (with maybe a little bit of a trend towards the 30-ounce). Very good 14 year old players swing a 31, 32 and 33 inch in almost equal numbers. We suggest you find the variable or two which discribes you best and go for the on the middle. Which, for most 14 year olds, would be a 32/29 BBCOR bat.
Notice, as well, that Tall players still tend to swing short bats. This has been the case forever. In fact, from the 100 surveys we collected on 14 year old BBCOR players the ones considered ‘tall’ were the ONLY ones that made up the 30″ inch bat space. Short players tended towards the longer bats. We find this observation fascinating and it holds true for basically every age group. Do smaller players feel they need more reach with a longer bat while taller players don’t quite care? The data doesn’t tell us.
The 32/29 BBCOR bat is the most popular bat for a 14 year old. No surprised there. However, we did find, on average, the 33/30 was rated as a bit too heavy for enough players to move into the ‘little too heavy’ category. That does not mean it was a ‘little too heavy’ for everyone. But, instead, that on average those who swung a 33/30 thought it was a bit much. It could be the right size for you and the alluvial diagram above should help clear that up.
Of some note, no 14 year old we surveyed has begun swinging a 34-inch bat just. As will be shown, there aren’t very many 17 year olds doing the same. In fact, at 14, the 32/29 becomes a great go to size for the next 3 years and, assuming the durability and pop is in tact, the bat might serve an entire high school career.
If you want some specific model recommendations then check our best BBCOR bats section.
The average 15 year old swings a 32/29 BBCOR baseball bat. There are more 33/30’s than 31/28’s but there are enough 31-inch BBCORs to still consider them. Our survey of over 75 15 year old BBCOR players is broken down by height, weight, strength and skill as well as bat size popularity and how happy the players are with their choice.
Like every age group we surveyed, very tall players tend to swing shorter bats. Tall players rarely swing larger bats when compared to the ‘average’ and ‘short’. We are not quite sure why this is but the data is so prevelant in each age set that it is impossible to ignore.
Of some note too, those who consider themselves excellent baseball players use a 32/29 way more often than a 33/30 and almost every one of those that consider themselves struggling swing a 33/30. So, when in doubt, swing the 32/29.
A bat size chart for a 16 year old is way more simple than that of a 12 year old. We measured both and below report the findings on the a 16 year old’s bat size chart. In short, the majority are using a 33/30 with a close second to a 32/29. Of the over 50 16 year olds we surveyed not one swung a 31-inch. There were several which claim to swing a 34-inch BBCOR bat and their survey data suggested they were perfectly fine with the size too.
In terms of trends and predictive value, the only real market we see is that short players tend to prefer the 33 over the 32. As well, those that consider themselves excellent make up the vast majority of the 34-inch 16 year old BBCOR market. There are no very strong players that want a 32-inch and very light players only want a 32-inch.
You’ll find the 33/30 at the plate in a 16 Year old’s hands about 15% more than the 32/29. 34/31 BBCOR bats for 16 year olds are rare but the users claim to be the same amount of happy. If you’re looking for the best BBCOR bat for a 16 year old we suggest you check out our best BBCOR bats article. In terms of sizing, we say stick with a 33/30 as a 16 year old if you’re not sure where you land. A 31 will be way too light and save the 34-inch for next year, maybe.
If you jumped to this section of the article you might like to know that we surveyed thousands of baseball players. We categorized them by age and built some charts to explain how bat sizes are divided up. The categories we used were height, weight, skill level and strength. You can follow along in this alluvial diagram as to what BBCOR bat 17 year olds use most often.
The 17 year old bat size chart is the cleanest of them all. Of some note, not a single player considered themselves ‘tall’ in this group of our surveys. We aren’t sure why that is–maybe just luck of the draw. But, as we’ve observed elsewhere, most athletes believe themselves to be shorter than average—not taller than average. We also found the fact that no player who considered themselves an average skill 17 year old swings a 32-inch.
By 17 years old everyone has figured out the bat size they like. In fact, the 3 bat sizes in the chart above (which the 17 year old players use) had the closest grouping of happiness in any age category. Not surprising.
If you want to get a better feel for what models we think are best then check out our best BBCOR bats page. In terms of the best size for a 17 year old we’d suggest go with your gut as you would know best at this point in your career. If this really is the first time you’ve played and you need advice we say go with the 33/30. If that doesn’t work, then borrow a teammates 32/29.
Another way to determine the right bat size is dependent upon the typical pitch speed seen and the size of the player. This infographic takes you through a mathmatical formula that determines the right bat weight size. This formula was derived from a paper by a physicist at a real university.
As we discuss below concerning bat size charts, there is good evidence any chart forcing bat size strictly based upon the height and weight of a player is incorrect. Skill level and bat weight load play significant parts in the actual right bat size. Charts are incapable of picking up that nuance.
With that said, we do think bat size charts can get you closer to the right size. We suggest you use the charts on the page as a starting point and then, after considering the write up below, choose your best bat weight. See this article too.
Bat Charts Lack
This isn’t due to a lack of trying. There are thousands of bat charts floating around the internet with every manufacturer, vendor and blogger using their own. Even academia got involved. Although still deficient (which we discuss below) it is our favorite bat size chart.
This table, they claimed, optimized the amount of swing speed per given bat weight to maximize batted ball distance based. The factors considered were height, weight and the player’s skill level. It sounded smart, because it was.
The intelligence of this smart bat chart design is apparent—with math and physics well beyond this blog’s ability to evaluate. Few have argued the table’s accuracy. But in a practical manner the table, like all bat size tables, fails to recognize three distinct items:
A bat size chart accounting for these items would look something like this:
Much to the surprise of many, there are actually THREE different weights for every bat you pick up. They are the Stated Weight, the Actual Weight and the Swing Weight. The stated weight is what the manufacture claims the bat should weigh. The Actual weight is what the bat actually weighs (which is often not the stated weight). The swing weight is a measurement of how much power it takes to swing the bat.
From a hitting performance perspective, the only thing that matters is swing weight. Yet, in bewildering fashion, the general public doesn’t have access to swing weights. Instead, we are left to consider the stated weight of the bat which is often inaccurate from the actual weight—neither of which would give you the swing weight.
As such, for example, a 30/27 BBCOR bat of any particular bat model may not have the same total weight of another 30/27 BBCOR. Even if the two bats did have the same total weight, they may not have the same swing weight. Due, in large measure, to the distribution of the bat’s total weight along its length.
In other words, not only is it likely that two different model bats with the same stated weight actually weigh differently, but how their weight is distributed along the length of the barrel makes the two bats swing weights often remarkably different.
If that concept of swing weight and total weight needs more clarification, imagine swinging a sledge hammer with the hammer portion in your hands with the handle as your bat. The sledge, you could imagine, swings rather easily. Now turn the imaginary sledge hammer around and swing by holding on the handle. Such a feat is much more difficult. The sledge hammer didn’t change it’s total weight at all, but it did change it’s swing weight. That swing weight changed because you moved the balance point of the object from more towards your hands to more towards the end. As such, the swing weight of the bat changed by simply changing the distribution of the weight along its axis.
Sadly, at the moment, no manufacturer is actively publishing their swing weights (often referred to as as moment of inertia or M.O.I.). The only way that we know of to calculate the actual swing weight of your bat is by this calculator here. Once you have a feel for the swing weight of your bat then you can begin comparing other bats swing weight.
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