Fly casting faults are frustrating in a specific way: the cast feels wrong, you cannot see what you did, and the advice you get is usually to try harder, which makes it worse.
This article is organized by symptom rather than by mechanics, because a symptom is what you actually have. Find the thing you are seeing, and the cause and the fix are underneath it.
One diagnostic note before the list. Nearly every fault below is invisible from where you are standing, because half of a fly cast happens behind you and the rest happens too fast to see. Turning your head to watch the back cast, and filming yourself from the side with a phone, will between them solve more problems than any amount of reading. Almost nobody does either.
Knots in the leader
The symptom everybody has and almost everybody misdiagnoses.
You keep finding overhand knots in the tippet. They are called wind knots, and the wind did not put them there.
They are tailing loop knots. A tailing loop happens when the rod tip dips below the straight path partway through the stroke, so the top leg of the loop crosses under the bottom leg. The leader flicks through its own line, and you have a knot. The fault happens whether or not there is any wind at all.
This matters because a knot in the tippet reduces its strength substantially, and because as long as you believe the wind is doing it, you will not fix it.
The usual cause is applying power too early in the stroke rather than building to the stop, which pushes the rod into a deeper bend mid-stroke and drops the tip. The other common cause is too narrow an arc for the amount of line you are carrying.
The fix is to start the stroke slowly and let the acceleration build to an abrupt stop, and to widen the casting arc as the line lengthens. Both are covered in the basic stroke, and both feel like doing less.
ORVIS Fly Casting Lessons: Fixing Tailing LoopsThe rod drifting forward, which you cannot feel
The single most common invisible fault, and the cause behind a great many tailing loops.
During the pause, while the line is straightening behind you, the rod tip creeps forward a few inches. It feels like nothing. What it does is shorten the arc you have left for the forward stroke, so all the power has to go into a smaller space, which produces exactly the tip-dip that tails the loop.
Creep is almost impossible to detect from the inside and completely obvious on video.
The fix is counterintuitive: drift the rod slightly further back during the pause rather than letting it come forward. Even a small deliberate rearward drift cancels the creep and gives the forward stroke room.
A cracking noise like a whip
You started the forward cast before the back cast finished straightening.
The line is still unrolling behind you, you apply the forward stroke, and the end of the line snaps through the turn. That is the sound, and over time it is also where flies go: a hard enough crack breaks the tippet at the fly.
The fix is the pause, which is exactly as long as the line takes to straighten and gets longer as you let out more line. There is no count that works. Turn your head and watch it.
The loop is wide and slow
The rod tip traveled in a curve rather than a straight line, or the stroke finished by decelerating instead of stopping.
Wide loops are not always a fault. They are what you want with a heavy nymph rig or a big wind-resistant fly, because they tangle less. They are a fault when you did not choose them.
The fix is a narrower casting arc for the line you are carrying, and a definite stop. Think about halting the rod rather than pushing it.
The line piles up at your feet
Usually no loop formed at all, which means the stop never happened. A stroke that eases off at the end hands the line no direction to travel in.
The other cause is slack at the start. If the line was lying in loose curves before you began, the first part of the stroke went into removing them and the rod never loaded. Start with the rod tip low and the line straight, every time.
The leader will not turn over
The fly lands in a heap short of where you aimed, with the leader collapsed.
Three causes, in the order worth checking. The leader is too long or too fine for the fly you have tied on, which is by far the most common and takes thirty seconds to fix with scissors. There is not enough line speed, which a haul solves. Or you are casting into wind, which has its own article and its own answers.
Check the leader first. People troubleshoot their casting stroke for a season while fishing a twelve-foot leader with a size 2 streamer on it.
Fly Casting 101: How to Fix Casting ProblemsEverything lands off to one side
A tracking fault. The rod tip is travelling in a straight line seen from the side and swinging around in an arc seen from above.
The cast can feel strong and still be inaccurate, because the energy went out in a direction you were not aiming.
The fix is a drill. Lay a rope or a hose on the grass and cast along it, checking that the line goes out over the top of it in both directions. Twenty minutes of that will fix a tracking problem permanently.
The back cast hits the ground or the water
Either the rod is travelling too far back, or the back cast is being aimed downward.
The usual culprit is the wrist. If the wrist breaks open at the end of the back stroke, the rod goes past vertical, the loop opens, and the line is thrown down behind you rather than out. A rod that stops around vertical, with the wrist firm, throws the line back and slightly up.
A useful check: make a back cast and stop, holding the rod where it finished. If it is pointing behind you at a shallow angle rather than standing up, that is the fault.
You keep hitting yourself with the fly
Two possibilities and they need different answers.
If there is wind coming from your casting-arm side, that is the cause and it is a genuine hazard rather than a technique problem. Cast backhanded, turn around and deliver on the back cast, or move. This is dealt with fully in fly casting in wind.
If there is no wind, your casting plane is crossing your body. The rod is travelling back on one side of your head and forward on the other, which puts the line through the space your ear occupies. Keep the whole stroke in one plane, on one side.
Either way, polarized glasses and a brimmed hat, always.
When it is the gear and not you
Worth checking before another season of self-blame.
A line that does not match the rod. Underlined rods barely bend and give you nothing to work with. If a rod feels dead, try a line one weight heavier before concluding you cannot cast.
A line with coil memory. Fly line stored on a small reel through a winter comes off in springs, and a coiled line will not shoot. Stretch it in sections between your hands at the start of the day.
A cracked or dirty line. Fly line that has gone rough or developed cracks in the coating loses its ability to shoot and sinks when it should float. Clean it, and replace it when the surface is visibly damaged.
A leader that has been in a spool since two seasons ago. Monofilament degrades, and old material breaks at knots for no apparent reason.
The loop climbs, or the fly hits the water early
Two related faults about the plane the cast travels in, and they are usually the same problem seen from different ends.
A back cast that climbs steeply upward means the rod stopped too early and too high on the back stroke, throwing the line up rather than back. It looks tidy and it costs you the load, because the line never straightens properly behind you and there is nothing to pull against coming forward.
A forward cast that dives into the water short of the target is the same plane problem in reverse: the forward stop happened with the rod tip already pointing down.
The useful mental picture is that the back cast and the forward cast should travel along the same line, in opposite directions, like a piston. If you were to draw the path of the rod tip in the air, it should be one straight line with the rod moving back and forth along it, not a V or an arc.
The fix is to pick an aiming point for the back cast as well as the forward cast. Most people aim the forward cast at a target and let the back cast go wherever it wants. Aim it at something, a treetop or a point on the far bank behind you, and the plane sorts itself out.
Faults that are actually decisions
Worth saying, because it prevents people from fixing things that are not broken.
A wide loop is a fault when you did not choose it and a tool when you did. Nymph rigs, indicators, split shot and big air-resistant flies all cast better on a deliberately open loop, because a tight loop brings the fly past the line at speed and tangles.
A cast that lands with slack in it is a fault if you needed contact and a presentation if you needed a dead drift.
A short cast is a fault if you could not reach the fish and good judgment if you decided to move closer instead.
The general point is that the goal is not a textbook cast. It is a cast that puts the fly where the fish is, in the condition the fish will eat it. An angler who can make a perfect tight loop and only that has one tool; an angler who can choose is properly equipped.
How to actually diagnose yourself
Four methods, in order of usefulness.
Film from the side. A phone on a bag on the ground, casting across the frame, shows you loop shape, arc, creep and stop with complete clarity. It is genuinely startling the first time.
Watch your back cast, in real time, by turning your head. Half the cast is back there.
Take the fly off and use yarn, so the leader end is visible and nothing can hook you while you experiment.
And change one thing at a time. The instinct when a cast fails is to change everything, which means you learn nothing from the one that then works.
Where each of these shows up
Tailing loops and creep get worse under pressure and at distance, which is why they announce themselves the moment you need a haul or a long shot.
Tracking faults matter most in presentation casting, where being a foot off the line ruins a drift that distance would not have affected.
Leader turnover problems show up worst in wind and in tight quarters, where the casting lane is short and the leader has no room.
And a cast that piles at your feet is worth diagnosing before you ever try a roll cast, because a roll cast is even less forgiving of a stroke that has no stop in it.
The gear
A phone and something to prop it on. The highest-value diagnostic tool in fly fishing and it is already in your pocket.
Yarn, for practice sessions where you want to see the leader and not hook yourself.
A rope or garden hose, laid on grass, for the tracking drill.
Line cleaner and a cloth, since a dirty line masquerades as a casting fault convincingly.
Fresh leader and tippet material, replaced more often than most people bother to.
A rod and line that actually match, or the willingness to try one weight up if the rod feels dead.
And an hour with a certified casting instructor, which is the fastest and cheapest fix on this list by a wide margin. Faults compound, and an instructor sees in ten seconds what a season of self-diagnosis may not.
The short version
Knots in your tippet are tailing loops, not wind. A cracking sound is a pause that was too short. A wide slow loop is a curved tip path or a stroke with no stop. A pile at your feet is no loop at all. A leader that will not turn over is usually too long before it is anything else. Everything landing to one side is tracking.
Creep is the invisible one: the rod drifting forward during the pause, shortening the arc without you feeling it. Drift back instead.
And film yourself from the side. It will tell you more in two minutes than this article can.
