Bat drop is printed weight, in ounces, minus printed length, in inches. For example, a bat labeled 13.5 ounces and 26 inches has a bat drop of minus 12.5 (13.5-26 = -12.5).
To get the right bat, you just need to match the right drop, weight, and length printed on the bat to the age, height, and weight of the player.
It’s that simple, right?
In actual fact:
- Printed bat weights are very inaccurate
- Bat weight distribution is different from bat to bat
- Bats are made of different materials, styles, and shapes.
In the rest of this article, I explain why these 3 factors combine to mean that selecting a bat is not so simple. In fact, these days, the concept of drop is in many cases more misleading than it is helpful.
Printed Bat Weights are Very Inaccurate
FilterJoe reader Chad Miller alerted me about the bat weight issue last year. This patent attorney and former engineer meticulously weighed a dozen bats and found that few of them weighed anywhere close to the weight printed on the bat. I bought a food scale and weighed many bats myself. What we both found is that actual bat weights range from 0.5 ounces less to 3.0 ounces more than what is stated on the bat. The majority of bats we tested were at least 1.5 oz overweight.
Think about that. Your child’s coach tells you that he needs a drop -12, 29/17 bat. So you buy a bat with these exact specifications. Your 7-year-old does much worse with this bat than his prior one. With a slow and awkward swing, he frequently misses the ball, and when he does achieve contact it’s usually a foul ball, weak popup, or weak grounder. One time, your kid hits one way over the centerfielder’s head. But overall it’s a disaster, with a batting average below .100 with the new bat. Why? Because, little known to you or your coach, it weighs 20.0oz, which is 17.6%% heavier than what you were expecting. You should be losing faith in the bat maker, not the coach.
Printing wildly inaccurate weight and drop on a bat is unacceptable, in my view. Yet that is the norm in recent years, not the exception.
Luckily, there’s a simple solution for both coaches and parents:
Weigh the bat!
Parents—before your player takes his first swing with a new bat, weigh it to make sure it’s the same as the printed weight. If you weigh a shrink-wrapped bat, be sure to subtract 0.3 ounces, the approximate weight of the bat’s shrink wrap. If the bat weighs 2 or 3 ounces more than the printed (and your desired) weight, you may want to return it for a lighter bat.
Coaches—as I detailed in Is Your Bat too Heavy, it’s a good idea to weigh everyone’s bats at the first practice, and then test everyone with soft toss to see if each player can handle the bat well enough to hit line drives. Players are often inclined to want to use bats that are too heavy for them, and this issue is compounded by the fact that most bats are heavier than the printed weight. When the players see for themselves what happens when they try different bats during soft toss, it will be easy to get them to change bats if necessary.
Why are the weights so far off? According to industry insiders, there are several reasons:
- Manufacturing variance can be as much as 0.25 ounces.
- BBCOR bats used by high school players are heavily regulated and cannot be lighter than drop -3. Manufacturers therefore need to target a weight that’s a little over the printed weight (.25 ounces would be reasonable) in order to insure compliance. If the target were .25 ounces heavier than printed weight, this would explain bats weighting anywhere from the printed weight to as much as .50 ounces too heavy (.25 over +- .25 from manufacturing variance).
- While bat weight is not so regulated for bats below the high school age, it could be that the same standards applied to BBCOR are applied to the rest of the lineup.
- Some bat makers print without tape (not sure how much weight tape adds—I suspect it would typically be 0.5 to 1.0 ounces).
- All the above might account for an ounce or so. Unfortunately, some manufacturers take advantage of consumer understanding of drop weights to extend their product line at minimal cost, typically printing a drop weight that best fits into a gap in their product lineup.
- The worst case of dishonest marketing is when a bat maker manufactures one model, but gives it two different paint jobs with two different printed weights. Consumers are misled into thinking they can get a lighter and easier bat to swing for the player, but in fact the bat they think is lighter is identical to the heavier bat. If any employees from bat makers are reading this—please stop doing this! From personal experience I have seen several batters who thought they were switching to a correctly-sized bat, but weren’t. Their batting average tanked. I have personally been able to fix such issues by weighing the bat and then telling the player or parent that they’ll have to delay using this bat until the player grows. But the vast majority of coaches have no idea that printed bat weights are so inaccurate. More likely, the typical coach will think that the player’s mechanics have worsened or that maybe it’s mental.
Baden Sports is more consistent than most bat makers. Every bat I have weighed from Baden is very close to 1.0 ounces more than stated on the bat. The axe-like knob design pushes the hands up the handle approximately 1/4″, which makes the bat feel lighter to swing compared to other bats, so slightly overstating bat weight probably makes sense for Axe bats.
DeMarini does things differently than other bat makers. They don’t print actual weight, but rather “swing weight” which they believe makes DeMarini bats more comparable with each other. This is probably true, as I’ll get to in the next section. But this may further confuse consumers comparing bats between manufacturers.
I haven’t weighed hundreds of bats so I can’t comment on accuracy from every bat maker. I have weighed quite a few Easton bats, though. Easton bats often weigh 2 to 3 oz over the printed weight, yet occasionally less than the printed weight.
Bat Weight Distribution is Different from Bat to Bat
To gain a full understanding of weight distribution in bats and bat technology in general, read Best Bats for Youth Baseball. To summarize:
Every kid intuitively understands that a ball will travel further when hit with a heavier bat, but that it’s harder to swing that bat. Most kids also understand that when you choke up on a bat, it’s easier to hit the ball, because the bat weight shifts closer to the hands. MOI is the technical term to describe how hard a bat is to swing. The definition is:
Rotational inertia, or the moment-of-inertia (MOI) is a measure of how difficult it is to change the rotational velocity of an object which is rotating around the pivot point. The larger the MOI, the more difficult it is to change the rotational speed of the object. The value of the MOI depends on the total mass of the object as well as the way in which the mass is distributed about the pivot point.
source: Daniel Russell’s MOI article
What this means in practical terms is that a bat maker can lower the MOI by distributing the weight of the bat towards the handle. The marketing term for this is “balanced.” Bat makers can also purposely shift weight to the fat part of the bat, the barrel. This is called end-loaded.
So let’s say there are two bats of identical printed specs, 30″ and 20 oz (drop -10). Furthermore, when you measure and weight these bats, they match the specs exactly at 30″ and 20.0 oz. However, one of these bats is very end-loaded, while the other is very balanced. A 4′ 9″ tall 11-year-old may be able to swing the balanced bat but have great difficulty achieving quality contact with the end-loaded bat. The end-loaded bat has a higher MOI, or swing weight, despite having identical length and width to the balanced bat.
Also, to state the obvious, a 30″ bat is going to be harder to swing than a 29″ bat of the same model that weighs the same and has the weight distributed equally. The measured MOI on the 30″ bat will be higher than that of the 29″ bat, because on a longer bat, the weight is further away from the handle.
This is why DeMarini may be on to something when it states swing weights instead of actual weights.
Personally, I would prefer a requirement for MOI to be printed on every bat and tested by an independent lab for verification before it can go to market. I get that MOI is a bit technical, but if these were printed on all youth baseball bats for several years, people would get used to that number and know that the higher the number, the bigger/stronger you need to be to swing the bat.
Unfortunately, MOI is not available to consumers, not even on bat maker web sites. So we’re left with the same solution as the prior section:
Weigh the bat!
Bats are Made of Different Materials, Styles, and Shapes
Drop is supposed to give you a rough measure of how difficult it is to swing the bat. I’ve already given two big reasons why it doesn’t in the prior 2 sections, but it turns out there are several other issues that illustrate how a simple focus on the drop of a bat may mislead a parent into getting the wrong bat for their player.
In my comprehensive article on youth bats, I already described materials, styles, shapes, and elasticity, so I won’t do so again here. I’ll just devote a brief paragraph to each of these issues.
Aluminum and composite are the two basic choices for bat materials. It turns out that these types of materials are not identical in terms of how the swing feels to a hitter. Generally, Aluminum’s stiffer nature makes it a little easier for a player to control, as opposed to composite which may flex a bit. Therefore, a player swinging 2 bats that are the same in every way except for material may be able to get better results with aluminum than composite. This is not to say there’s anything wrong with composite—a player may do fine by using a slightly lighter or more balanced bat.
There are many styles of bats that have an impact on perceived swing weight or bat control. The Axe bat has an axe-like knob that pushes the hands 1/4″ up the handle, effectively lowering the MOI and swing weight of the bat. The Anderson Techzilla bat has a double-walled aluminum barrel, which makes it the most end-weighted bat on the market and thus much harder to swing than bats of similar weight and length. But the most common stylistic difference is one-piece versus two-piece bats. Most players find it easier to control one-piece bats, because two piece bats flex at the junction between the handle and the barrel. As with the aluminum/composite divide described in the prior paragraph, it may be that for many players, the only way to control a two piece bat sufficiently well will be to get a lighter (higher drop) bat than they would if it were a one-piece bat.
The shape of a bat varies depending on the length and width of the barrel. The 3 common widths are 2 1/4″ (youth), 2 5/8″ (big barrel), and 2 3/4″ (senior). For the youngest players, 2 1/4″ is generally easiest to control. However, having a fatter or longer barrel can allow balls to be hit well into play that might otherwise have been weak grounders or popups on a 2 1/4″ bat. What does this have to do with drop? How the bat feels when swinging it will be different if the shape of the bat is different, even if everything else is the same. You can’t necessarily expect that two bats with identical MOI, materials, and style will necessarily swing the same, if their barrels are shaped differently.
Final Words of Advice
I think drop may have been a good idea 20 years ago, in an attempt to make it easier for bat makers to describe their bats, and for parents to buy the correctly-sized bat for their player. But given that bat weights are often not stated correctly, along with many other factors I mentioned above, the term has come to have much less value for buyers than it used to.
The best industry-wide solution would be to require MOI to be printed on every youth bat, along with independent lab testing to insure that the actual MOI is within a reasonable percentage of printed MOI. That’s probably not going to happen any time soon.
The simplest thing a bat buyer can do at this point in time is:
Weigh every new bat before use!
Even better is to make sure a coach or someone else with baseball knowledge observes hitting soft toss into a net, as described in Is Your Bat too Heavy.
It’s an unfortunate fact that buying a baseball bat has become so complicated in recent years that it takes a lengthy guide to describe it all. I have seen many players quit baseball because they struggle so much to hit the ball. I always wonder how many players quit because they were using the wrong bat. Weigh the bat, and you won’t have to wonder if swinging a too-heavy bat is driving a player’s desire to give up the great sport of baseball.