What is a clicker
In a nutshell
A clicker is generally only used on a recurve bow and lets the archer know he has drawn the bow back to the correct draw length or to full draw. It gives an audible "click" and only on the sound of the clicker will the archer release the arrow.
A clicker can be a strong piece of wire, but mostly is made of tensile spring steel or a magnetic wire arm or carbon, about 6.35mm or 0.25 inch wide and 76.2mm or 3 inches long and is attached to the riser by a screw. It is mounted in the sight window or on the side of the riser with the top of the clicker screwed or attached to the riser and the bottom of the clicker hanging downward past the arrow shelf which supports the arrow while it is drawn, extending to just in front of the arrow rest.
How it works
The arrow is placed under the clicker - between the clicker and the riser, so that at full draw, the arrow point will be pulled from under the clicker. The clicker will then snap back against the riser making an audible "click" sound. This sound and the slight vibration it causes in the riser, tells the archer that the bowstring has been pulled back the proper distance for consistent arrow speed.
What's in it for the archer
With practice, experienced archers often report they no longer hear the click, but instead they sense it as part of their overall mental game. Many archers train themselves to shoot automatically when the clicker drops off the arrow.
The correct draw length
Before an archer can use a clicker successfully, his precise draw length needs to be ascertained. Often the initial draw length measurement taken varies from subsequent measurements and it is of vital importance that his correct draw length is established. Clickers are adjusted to the arrows the archer will use in competition.
Draw length check
The clicker is also used as a draw length check. The position of the clicker is adjusted so that when the archer reaches full draw, the clicker just begins to slide down the arrow tip. When he is satisfied the shot is set up, he increases back tension. As back tension increases, the draw hand moves the bowstring and the arrow back, so that eventually the arrow slides out from under the clicker. The clicker slaps the riser and makes a noise, hence its name. Archers generally watch the clicker to see that the length of the draw is sufficient to place the clicker on the start of the slope of the arrow tip. After that, visual focus switches to aiming.
The clicker facilitates the use of back tension, plus it discourages anticipation of the release because the archer is never quite sure when back tension will have increased enough to slide the arrow from under the clicker. For finger shooters, these are important advantages in setting up consistent and well executed shots. Most Olympic style shooters use one, but finger shooters in bowhunter class often are not allowed to use clickers.
Consistent draw length
Another advantage of using a clicker is an identical draw length on every shot. Draw length doesn't vary, so the thrust imparted to or forward propulsion of the arrow doesn't vary even slightly on any shot. Each arrow can then be shot from the exact same draw length.
Do all archers use a clicker
Some archers master the art of sensing the click or that their arrow is at full draw and discard their clicker, while others keep it on their riser and use it as a constant check. The clicker significantly improves many archers' abilities to be consistent in their shooting.
Who invented the clicker
Fred Leder is the man who invented the clicker and developed the technique that many archers use today. His idea was to get away from using the eye as a triggering mechanism and instead use the ear as an audio trigger. Fred figured out that a small piece of spring steel screwed to the bow riser that would go over the end of the arrow and 'click' out of the way with slight pressure, might just solve the problem. His first clickers were made from wind up clock springs. In late 1957, he experimented and practised in his basement archery range and by the next spring, he was competing with the best in the area.
The clicker was affixed to all of Fred's family's bows and the results were quite dramatic, with their scores going from just another archer in the field, to winning many events, local, state and national. However in 1961 in Crystal Springs, Arkansas, USA is where the clicker was really noticed.
As a 16 year old, shooting in the intermediate division, Fred's son, Jim's scores were almost on par with the senior men's division. It wasn't long before Earl Hoyt of Hoyt Archery started selling clickers attached to a small bit of leather that had an adhesive backing and the rest, they say, is history.