For anglers, the ability to tie good knots is one of the most important requirements for fishing success. Too many times knots prove to be the weakest part of a fisherman's outfit.

A proper knot often means the difference between only hooking a good fish and landing it. There are hundreds of different knots but for most of us the ability to tie three or four properly is all that's required as far as fishing is concerned.

Most anglers are familiar with a fly to leader knot called, among other names the clinch knot. This was a tremendously popular knot in the days of gut leaders because it could be untied by merely scraping with a thumb nail. Silk worm gut was expensive and quality varied greatly, so if an angler acquired a leader that performed well it was only natural to be reluctant to waste any by cutting it to change flies. On the other hand nylon is weakened by untying and retying.

The clinch knot is tied by putting the leader point through the hook eye, doubling it back on itself for two or three inches, twisting the fly four or five turns to wind the leader around itself then inserting the leader end between the hook eye and the coils, hold to prevent untwisting and tighten.

A favorite maneuver of large fish when hooked especially brown trout, is to try to free themselves by rubbing the fly against gravel or rubble on the stream bottom.

This is what causes the vibrating sensation you sometimes feel in the line when playing a fish. It may not free the fly but it certainly can untie a clinch knot.

A large brown trout can loosen that knot by scraping it against the bottom just as surely as a fisherman can with his thumb nail.

The clinch knot can be made more dependable by going one step farther in tying it. This consists of slipping the leader end through the loop made when the leader is inserted between the hook eye and the coils before pulling tight. This is called an "improved" clinch knot, but, from this writer's experience, can still come untied when scraped against the bottom.

The clinch knot is usually adequate for pan fish, but there are more dependable ones for large fish. It is described here because it is widely used under a variety of names and this should enable you to recognize and avoid it.

A much more reliable fly to leader connection is one called the "turle" knot. It is as easy to tie as the clinch knot but must be cut to change flies. To tie it, pass the leader end through the hook eye from the front and slip the fly up on the leader out of the way. Make a slip noose in the tippet end but wrap the leader point through the overhand knot loop twice before tightening. A simple slip knot would have the point wrapped through only once. Winding the end through the knot twice is very important when working with nylon.

Now slip the fly through the noose and draw on the leader to tighten the noose around the fly head just back of the eye. When used on turned down or turned up eye hooks it insures a straight pull on the fly. For ringed eye hooks, tighten the knot in the eye itself.

All knots in nylon should be wetted and then tightened carefully and evenly. Wetting lubricates the nylon which helps the knot seat properly and increases its resistance to slipping or breaking.

Nowadays most fly fishers purchase ready made leaders, but often they extend them by tying a strand of lighter nylon to the leader end for a tippet.

There are two widely used knots for doing this, the "blood"knot and the "surgeon's" knot. Of the two, the surgeon's knot is easiest to tie and is the best one to use where there is a dissimilarity in strand sizes of more than a few thousandths of an inch. It works good with strands of equal size also.

Tie this by first laying the two strands parallel with about four inches overlapping and, treating the overlap as a single strand, make an overhand knot. However, instead of wrapping the combined ends through the loop once and tightening, make an extra turn through and then tighten slowly and evenly. Moisten the knot, tighten again and cut off the excess.

Sometimes when fishing with wet flies or nymphs it is advantageous to fasten a second fly back several inches from the point fly. This is called a "dropper" fly and is usually secured with a piece of monofilament, to the main leader about where the tippet is tied on. This strand, so it won't twist around the leader, should be stiffer than the tippet and much shorter.

To attach a dropper fly, simply tie the fly to a short strand of leader material using a turle knot, then tie a loop knot in the other end. The dropper strand should not be over four inches long including the loop. Next fold the loop around the leader above where the tippet is knotted on, pass the fly through the loop on the other side of the leader and pull tight. Slide the loop down against the tippet knot and pull tight again.

The doubled part of the loop stiffens the dropper and makes the fly stand out away from the main leader, which helps discourage tangling.

The connections that give fishermen the most trouble are the fly to leader knot and the one that ties leader strands together. Failure of one or the other of these two knots has lost more good fish than any other item of an angler's gear. Practice the turle and the surgeon's knot until they become second nature. Always moisten the knots to help them seat properly and tighten carefully.

When tied properly the turle is one of the most dependable fly to leader connections and the surgeon's knot is ideal for fastening a tippet or building a complete leader.