They are there to lend a hand to help collect all the loose balls from delaying a sporting event, yet ball boys and girls don't always do their jobs to perfection.
And we shouldn't be too surprised by that.
With baseballs screaming toward them in foul territory, tennis balls bouncing crazily out of their reach and the action sometimes moving too fast to keep up with, it can be difficult to do a job well done.
Since not all of them can be as spry as Kramer, here are the most embarrassing ball boy and ball girl fails from sporting events.
As if jumping onto the court wasn't bad enough, this poor kid got one of the biggest death stares I've ever seen when Viktor Troicki glared at him as if he just stole something.
Come on, kid. You've got to keep your eye on the ball—even if you're not participating in the sport.
Given that a tennis ball flies off of a racket at insane speeds, this young ball boy is really lucky that the ball wizzed by him and not right into him.
Sure, the shot was "just a backhand," but that's like saying getting shot with a rubber bullet doesn't hurt. Ask Johnny Knoxville, it certainly does.
The good news is, this kid didn't have to find out for himself.
Like the first kid I showed you who came onto the court a bit too prematurely, this soccer ball boy got a little overzealous with trying to do his job.
In his defense, the ball did take an unusually long time to roll from one end to the other, but still, the ball boy should know better than to just march onto the pitch and scoop it up.
Tennis great Andre Agassi has plenty of good moments from his career—but this isn't one of them.
After pulling a quick trick shot after the ball was ruled out, Agassi's shot seemed to fake everyone out—including the poor ball boy who got nailed by the fuzzy, yellow ball.
The kid may not have been on fire, but that didn't stop him from pulling the safety tip told to every single kindergartner if he or she should ever smell a fire.
Actually, to save his embarrassment, I hope that this ball boy actually claimed to have smelled smoke—because he looked quite foolish otherwise.
While there were a few close calls earlier, this ball boy wasn't as lucky, getting smashed in the side of the head with a monster forehand.
At least the tennis player who hit him came over and apologized. But that still probably didn't make the kid's headache go away.
After being razzed by some of the members of the Oakland A's bullpen before the game, ball boy Kevin Fennell found out that, sometimes, ballplayers know best.
Handing each foul ball that came his way to one special fan all night, Kevin was able to land both a hug and what appeared to be a peck on the cheek. He also landed a date with the girl, named Jacki Lynch.
Hell, the two even got national attention for it.
It's never easy to regain composure after one loses his or her balance.
This ball boy found that out firsthand when he stumbled out of the gate and ultimately ate it on the hard courts of the U.S. Open.
He immediately curled up and hid himself, but the broadcast then didn't do him any favors by replaying the fall over and over.
All this dude was trying to do was help a brother out, offering to hand tennis player Andy Murray a towel in between points.
What happened next was something that I hope the kid hasn't seen again since—he was stood up as if Murray was an attractive girl at the bar.
Don't worry, dude, just wipe yourself off and get back out there.
This girl doesn't seem to understand the purpose of a ball girl, does she?
When given the opportunity to sit on the field wearing a glove, the one thing she should absolutely know to do is to pay attention to the game.
While she does that by knowing where the ball is, girl has to do a better job at getting herself out of the way and not just sit there with huge players running down on her.
The only saving grace for this ball boy was that the surface he just happened to slide on was grass, meaning he wasn't left with as many scrapes and bruises as he would have been had he done this on a hard or clay court.
Still, that doesn't mean he didn't make an ass out of himself.
The bad news?
This Tampa Bay Rays ball boy let the ball skip right through his legs when the ball came to him, hopping up into the player bench and hitting a few in the arms and face.
The good news?
He redeemed himself later in the game by snagging an absolute screamer.
Will the real ball boy please stand up?
As I mentioned in an earlier slide, the one responsibility of a ball boy/girl is to know what's going on at all times.
This Kansas City Royals kid must have been sleeping through that part of training, because he really ignored that rule.
Thankfully, he didn't collide with a charging Rajai Davis—which seemed inevitable—but that didn't save him from getting razzed by the announcers while he sulked in his chair over the gaffe.
I get it—tennis isn't the most action-packed sport to watch.
That doesn't mean that someone should fall asleep during a match, especially if that person is a ball boy.
OK, so this kid seems like he was just dehydrated and that's what led to him fainting, but still, poor look on his part by getting carried off the court.
I can't help but think that playing a ball off of a ricochet isn't difficult to do.
So when this Hooters ball girl was put in the predicament after a foul ball, she looked less like someone incapable of doing a job well and more like one who just got unlucky.
Still, everyone learns early in baseball that the key to scooping a ground ball is staying down—and she didn't do that well at all.
Anyone who has ever tried hopping over a wall or fence at full speed knows that it's a risky proposition, because anything can happen.
When executed perfectly, the jumper is unscathed and walks away fine.
But when failed, this happens, with a foot typically catching onto something and the jumper falling on his or her face.
Having that happen in a live televised tennis match might be one of the worst spots to have it happen, as this kid found out.
Just when you think you're the cool kid because you've got a front row seat at a soccer match, something like this happens.
A deflected ball off a back wall ate this kid alive, knocking him to the ground and making his friends who had to pay for a ticket laugh at him for sure.
There are athlete trash-talkers, and then there are ball boy trash-talkers. This kid is definitely the latter.
I know that soccer fans are often described as passionate and even hooligan-like, but I would have never thought that that intimidation also included the ball boys.
Seeing this kid have to be held back from going after an opposing goalie makes me fear for the amount of detentions he gets for standing up to his teachers in middle school.
OK, so after seeing a few Hooters girls step in as ball girls during spring baseball games, it seems it might be time to hire some other people.
Sure, they look pretty and all, but if they aren't good at doing the job, what's the point of having them down there?
This girl must have just been used to handing out food to customers, which made her do that very thing—except she used a live baseball.