Interestingly, the flip side of that question ("What's the best glove for my kid?") is rarely asked. (At least in my experience.)
Bats can definitely be a complex world. Different sizes of barrels. Different lengths. Different weights. Different drops. BBCOR. The new USA Baseball standard. Composites/aluminum/etc. Easton/DeMarini/Louisville Slugger/Axe/etc.
No wonder many parents are confused.
Common flawed solutions
The most common advice for how to find the best bat is to have the child hold the bat with the arm outstretched. If the kid can hold the bat without struggling for a certain number of seconds, then the bat is considered a good weight.
Nothing against JustBats.com but they mention this test in one of their videos.
The biggest problem with this weight test is that pesky "certain number of seconds". That number can vary depending on who is offering the weight test as a solution. This site says 10 seconds. This site says 20 seconds. This site says 30 seconds. (For the record, JustBats.com was in the "10 second" camp, without explaining why 10 seconds is the recommended number of seconds.)
Clearly, the "number of seconds" criterion is contrived, arbitrary and subjective, and should therefore be eliminated.
Interestingly, when I googled "bat weight test," the first result was from a site called "Filter Joe". Joe's top recommendation was not to have the kid hold the bat out, but to do soft toss. Joe's thought is that whatever bat the kid hits the most line drives with is the winner. This is certainly better than the "number of seconds" test but it still has several significant flaws.
First, the bat evaluation is at the mercy of the tosser. Unless the tosser makes perfect tosses 100% of the time, then the results will be skewed. Bats swung against poor tosses get an unfair evaluation. Second, if a kid is hitting line drives with more than one bat, how do you narrow down from there? Third, swing fatigue starts to set in as a kid takes more and more swings, which can affect the production and quality of line drives with bats swung later in the sequence.
Still other sites like this one have charts that try to determine what size bat your kid should use, based on your kid's weight and height. Noble idea, but who came up with the numbers in that chart? You could have two kids who weigh the same and are the same height yet swing differently and have different ideal bats.
So what's a parent to do?
My recommendation
The most unbiased way to evaluate a bat is by measuring exit velocity off the bat when hitting off a tee. The tee is necessary because it eliminates the variable of poor tosses or pitches. But how do you measure exit velocity? Well, I have good news and bad news. Which do you prefer to hear first? The bad news? Glad to oblige 🙂 The bad news is you have to use a radar gun. There is simply no other way to accurately measure exit velocity. And because you use a radar gun, tee and real baseballs, you can't go to a sporting goods store and test all their new bats on the rack with this technique. The good news is that you can use this technique to see, for example, which bat among the team is best for your player to use. And regarding a radar gun, Pocket Radar makes an affordable radar gun that fits in the palm of your hand, is as accurate as Stalker guns and Juggs guns, and is cheaper than Stalker & Juggs. In my mind, Stalker was the gold standard for baseball radar guns. It looked like the type of radar gun that policemen use to nail speeders, and was commonly seen in baseball stadiums by scouts. But the cheapest Stalker is the Stalker Sport 2, ringing up at a hefty $500 (which is actually cheaper than the Stalker Sport 2 sold on Amazon, which are fetching $550). But I recently came across Pocket Radar, Ball Coach version. It's not bulky like the Stalker gun; it's the size of a smartphone, fitting comfortably in one hand. More importantly, it's just as accurate as the Stalker guns. And most notably, it's 40% cheaper than a Stalker Sport 2 at $300. The really neat thing about the Pocker Radar is that you can use it to measure other things as well: pitching velocity, throwing velocity, exit velocity in a game, and more. You can use it, for example, to measure your team pitchers and challenge them to beat their fastest speed at each practice, which helps ensure they are practicing their pitching with purpose. The Pocket Radar is an indispensible tool that I keep in my equipment bag at all times. The way I evaluate multiple bats is:- Set up a baseball on a tee and have the batter take about 5 or so swings off the tee with each bat
- Stand behind the batter with the Pocket Radar as he swings and measure each swing's exit velocity.
- Take the average of each of the 5 swings for each bat, also noting the max speed of the five swings.