Learn your first ranger skill in just 14 Days: https://link.dashrendar.com/opt-in
Even if you have no land, no time, and don't want to take on a whole project.

Just the increase in range makes the strap worthwhile, if you army is using it and the enemy aren't, instant advantage

Greek: It's Zeus!
Roman: It's Jupiter!

Indo-European: Skyfather is Skyfather!!!

Old Norse literary sources mention the snærisspjót, which seems to have been a string or strap used to increase the range and accuracy of a spear throw, as used in "Fljótsdæla saga".

As a kid over 60 years ago we did something very similar.  We took a length of stout string with a knot at the end, and cut a circular groove around our "spear", about an inch from the base end. The knotted end was looped around the shaft behind the knot and drawn tightly along the shaft towards the balance point, or grip point one would normally use to throw the spear. This end was held tightly in the throwing fist, keeping the string tight, to hook behind the knot. One then threw the spear as per normal but extending the throw till the string disengaged from the knot.
We regularly achieved at least double the distance as before and, as we got better, even more than this.  It works like the atlatl, but easier to control.  
It was a great deal of competitive fun!
Cheers mate!

Greek - "You can't just keep taking ideas and passing them off as your own!"
Roman - "See yeah, you would think that."

The truest words are even said in jest.

I’m a simple man, Dash throws, I watch, and I like.

Tod Cutler is a class act.  Cool to see him contribute.

Similar to an atlatl, the cord extends the amount of time you are able to add momentum to the javelin. The further back the cord is attached, the longer you are able to continue pushing the javelin after initial release. Also, if it's connected near the back of the javelin, it will add a small abount of drag to the the rear, and help to stabilize it, similar to fletchings on an arrow or atlatl.

As a kid in the mid 60's, I made a pilum, a sling, a bolo and an onager. I had to get my descriptions from history texts. It was a lot of fun, but I was alone out in that field. It is so great to see what the internet has allowed people to accomplish now. I love your videos and keep up the good work.

Wood stick: Nice
Pointy wood stick: Good
Pointy wood stick plus string: Better

If you make a knot in the cord, wrap it over itself, it grips the shaft, you dont need to let the cord go with the spear, you can even use this with an arrow, we used to do this with home made javelins and arrows as kids 50 years ago, show to me by my Father who had learned of his Father, going way back, this was common knowledge in Scotland and Ireland with throwing weapons

Interesting tests like always. ❤

I wanna know who’s the guy that said “Hey let’s light these pigs on fire and send them at the enemy.” Now that’s a terrifying weapon.

With the string added you essentially build an Atlatl with a different point of contact.  The applied leverage arm from the Atlatl is similar to the Ankely.  The Atlatl applies rotation through the fletchings, the Ankely through the wrapped string.  Possibly a detaching string more towards the rear of the javelin would increase the leverage arm and possible even increase the achievable distance.

Great test, Dash, as always.
Getting Tod's attention on one of our videos is always a highlight!

Used to make something similar as a kid, but not full length spear, more like a long heavy arrow with flights.    We'd make a notch towards the rear 1/3rd and have a knot in the end of a string - you'd hold the sting across the width of the arrow with your thumb, wrap it around the shaft and behind the knot - then keep tension on the cord which clamps the knot against the notch.   Wrap the string a few times around your fingers and hold the arrow towards the front 1/4 or 1/5 at a guess.  maybe closer to the point.     As you throw, like an atlatl, you get the huge leverage but the half turn of the string adds the rotation you're talking about too.    As the arrow passes by the knot simply drops away as it "unlatches".    Accurate and powerful, with the bonus that you retain the throwing lever (the string) for followup arrows.    

Do the records show that the leather thong was released WITH the javelin?  seems like a waste of material and risks the weapon being used back against you, since they will have the same leverage.  If the string it retained, you would outrange any return they could make

My thoughts :)

Native Alaskans did this with their harpoons and the "rope" connecting them to their "bouys", although ours were made to avoid spinning. They weren't really trying to increase range, but trying to increase the depth of penetration at short ranges.

P.S. Try tying the cord at the head, then running down the shaft, over the butt and back to your gripping point to work like an atlatl.

As I'm watching this, it made me think of an epic moment in history from the Roman Civil War when Ceasar was fighting the Pompeian/Optimate faction. It was the Battle of Ruspina in North Africa, and Ceasar's forces were fighting Labienus, his former right-hand man. Labienus was on horseback, riding in front of the Cesarean troops and taunting them, basically calling them a bunch of inexperienced newbies who didn't know what they were getting into. "I truly pity you!" Labienus shouted at them. A man stepped forward and said "I'm no raw recruit!" and Labienus shouted back to him: "Who are you, then? Where is your standard?" ... the man said "I shall soon make you sensible to who I am!" and he casually took off his helmet, grabbed his javelin and crow-hopped and hurled it as hard as he could. It skewered the horse through the chest and sent Labienus smashing into the ground painfully. "Know Labienus, that this dart was thrown by a man of the 10th Legion!" he yelled. 🏆

As kids in the UK we used string to launch home made arrows. We’d call them Dutch Arrows, for no reason at all apparently. But they’d fly at  a hundred yards plus.  Once I even got one to stick into a tree. The string had a knot in the loose end  and wrapped around the shaft near the flight end just once. Then holding the string taut and  near the front of the shaft with the same hand you let fly very similar to the demonstration.