Why it's important to study it
A lot of fishermen hold that only one type of slack line cast is all you need, just a few wriggles here and there to avoid drag in most cases. This way of thinking is like believing that an Adams is a fine pattern for any situation, day and point in time. Actually, there are plenty of circumstances where a specific alternative to an attractor will get much better results.
The most important priority when you need this type of cast is to always try to throw the right amount of slack line, whether it's wriggles or a pile. If all you need are two or three little wriggles at the end of the line, even an extra inch of slack line on the water would be undesirable. The reason why this is top priority is clear...you'll be more accurate and you'll set the hook better.
The next important parameter in executing a slack line cast (SLC) is exactly where that extra line lands. You have to learn to read the water so you can decide whether you want slack line in one of these positions:
- near the rod tip
- half way to the end of the line
- at the end of the line
- only in the leader
- at your feet
- behind you
- spread regularly all along the line.
Mastery of as many SLCs as possible and knowing how to control their variables will allow you to land the right amount of slack line at the right place. Moreover, you'll be able to choose the most suitable cast based on the following parameters:
- Whether it's windy or not and, if it is, the direction of the wind.
- How accurate you have to be (fishing the water or casting to a trout rising in a difficult lie).
- Whether you need a soft lay-down (slow water, currents and type of fly).
- If there's some specific cast that you haven't yet mastered.
You can choose to fish with a couple of attractor imitations (a few almost subconscious wriggles in the line) all season or to try to find the most suitable pattern for each situation (mastery of all the SLCs). Its a fairly personal decision. My advice is that the more you know and can apply on the stream, the more fun it'll be (you may even hook more fish). And what's much more important, you'll appreciate your surroundings more.
Some anglers always use their favorite general pattern no matter what insect is hatching. Likewise, there are some that always make the same presentation cast no matter what currents lie between them and their target.