At the risk of being negative, one of my pet peeves is the use of the word "feel" in lessons, clinics, or while training horses. I don't mean, "Can you feel that these bristles are softer than the hard brush? That's why we use the soft brush for a final polish on the horse's coat"... In the horse world, particularly in certain genres of horse training, "feel" is one of those mystical phrases that everyone uses but never explains. It's a vague indescribable quality that some horsemen have and some don't, but good luck trying to find someone to explain what it actually is or how to get it. It's extremely common to hear things like:
"Feel is THE most important thing"
"Without feel, you will never accomplish your goals"
"That person has a great feel of her horse"
"You must learn feel"
"A person either has a good feel or they don't"
All these statements beg the question, "Then, dear Equine Guru, do share with us, what exactly is 'feel' and how do I learn it?" Most of the time, responses are merely a repetition of how important feel is, and declaring you either have it or your don't. I don't find this line of conversation particularly helpful, and it certainly doesn't describe what "feel" is. As a result, I don't use this expression.
"Feel", as often used in the horse world, is really just timing. Horsemen tend to use the word feel when they mean a person did a good job of releasing pressure at the appropriate time when training with negative reinforcement. For example, if I'm lunging a horse and trying to get him to step forwards, I'll sometimes lift my whip off the ground to put psychological pressure on him. As soon as he takes a step forwards, I lower the whip. Applying the negative stimulus (lifting the whip) to get a certain behavior (stepping forwards), then ceasing the negative stimulus when I get the desired behavior is called negative reinforcement.
If I do it with correct timing the horse will learn that he should step forwards to avoid the discomfort of the whip getting higher in the air and closer to him. If I repeatedly do this with correct timing, one might say I have good "feel" with ground work. The phrase is a gross oversimplification of basic behavioral psychology techniques. One does need a better understanding of behavioral psychology to explain using a lunge whip correctly, as well as more words to truly explain, rather than just labeling it "feel".
When riding, "feel" is also about timing. If a rider consistently applies a leg aid at the exact right time to get the correct lead at the canter, you'll hear people say "she has a good feel for canter departures". A more accurate way to explain what happened is to say the rider pressed her horse's side with the calf of her outside leg at the instant the horse's outside hind leg was pushing off of the ground. When the horse pushes off into the canter with the outside hind leg, the horse will be on the correct, or inside, lead at the canter due to the pattern in which the legs move at that gait. One needs a good understanding of equine gait analysis to explain cuing a correct canter depart, as well as more words to truly explain rather than just labeling it "feel".
Sometimes you'll hear that a rider "took a feel of the horse" in preparation for a jump, a hard stop, a fast turn, or some other athletic maneuver. In this instance it merely means the rider shortened the reins slightly, or moved her hands so that she could literally feel the horse's mouth with her hands through the reins and bit. This also has to be done with correct timing, since it is a way to rebalance a horse in preparation for the maneuver. One needs a better understanding of equine biomechanics and how the rider's hands affect it, as well as more words to truly explain rather than just labeling it "feel".
So really, "feel" is timing. It's the ability to communicate with the horse using aids or cues with correct timing and strength, when applying or removing them. It takes more words and a deeper understanding of the subject at hand to explain the how and why, rather than just calling it "feel". Next time you hear an instructor proclaim the necessity of feel, see if you can figure out how timing of aids would influence the situation. And if the instructor won't explain the how and why, perhaps they're using "feel" as a cop-out because they don't understand, or can't explain the particulars of the behavioral modification technique.