There's a generational argument about free kicks that goes roughly: the old greats bent it round the wall with pure technique, and modern players just hit it and hope the ball wobbles. Like most generational arguments it contains a real observation and a wrong explanation.
The observation is correct — free-kick technique has genuinely changed. The explanation isn't about players getting lazier. It's mostly about the ball.
What changed physically
Footballs used to be made of 32 stitched leather panels, with visible seams and a fairly rough surface. Over the last twenty-odd years that's been progressively replaced by thermally bonded balls with far fewer panels — sometimes as few as six or eight — and much smoother surfaces with engineered textures.
Fewer seams means less surface roughness in a conventional sense, which changes how air behaves around the ball. And that turns out to matter enormously for a struck free kick, because the entire behaviour of a ball in flight depends on the boundary layer of air clinging to its surface.
The short version: smoother balls with fewer seams are more prone to unpredictable lateral movement when struck with little or no spin. That's the knuckleball effect, and it's much more achievable with modern balls than it was with a heavily stitched one.
The two techniques
Broadly there are two ways to hit a direct free kick and they're almost opposites.
The curled shot. Struck with the inside or instep, imparting heavy sidespin. The spin creates a pressure differential — the Magnus effect — which curves the ball predictably through the air. The classic technique, requires precision, and the flight path is smooth and readable once it's underway.
The knuckleball. Struck through the centre with minimal spin, usually with the laces or the toe area, with an abrupt stop rather than a follow-through. The ball travels with essentially no rotation, and as it decelerates through a critical speed range the airflow around it becomes unstable, producing sudden lateral movement.
The knuckleball is much harder to keep on target and much harder for a goalkeeper to read, because the movement happens late and isn't predictable even by the taker.
Why keepers hate the second one
A goalkeeper facing a curled free kick has a genuinely solvable problem. The ball's trajectory is established within the first few metres and the movement is smooth. An experienced keeper reads the flight and gets across.
A knuckleball offers no such information. The ball leaves the foot travelling straight, so the keeper sets for a straight shot, and then somewhere in the last ten metres it moves half a metre in a direction that couldn't have been predicted from anything.
That's why the saves look so awkward — the keeper isn't beaten by pace or placement, he's beaten by the ball doing something after he committed.
The wall changed too
Separate development but related. Free-kick walls used to be relatively static objects that stood there. Now there's a whole set of behaviours around them.
Jumping is the obvious one, though there's a decent argument it's counterproductive — a jumping wall creates a gap underneath it, and a fair number of free kicks are now hit deliberately low under a jumping wall. Some teams have started instructing walls not to jump at all for that reason.
Then there's the player lying on the ground behind the wall to block exactly that low route, which arrived a few years back and looked absurd for about a season before becoming completely normal. And the rule requiring attacking players to stay a metre away from the wall, introduced because the attacking-player-in-the-wall trick had become too effective.
All of this is a small arms race around a set piece that produces maybe one goal in twenty attempts, which tells you something about how marginal the gains in football have become.
Does distance matter differently now
One practical consequence worth noting. The knuckleball is most effective from a specific distance range — roughly 25 to 32 metres — because the ball needs to decelerate into the unstable airflow zone before it reaches the goal.
Too close and it arrives before the instability develops, so it's just a hard straight shot. Too far and it's lost too much pace to threaten.
The curled technique doesn't have that constraint in the same way, which is why you still see it used from closer, wider positions where the geometry demands bend rather than movement.
Good takers pick based on the position. The ones who only have one technique take the same free kick from everywhere and it shows.
Is it actually harder now
The conversion rate for direct free kicks has, if anything, drifted slightly downwards over the last couple of decades, though it varies by league and the samples are small.
That's slightly surprising given the ball changes. The likely explanations are better goalkeeping, better wall organisation, and the fact that referees award fewer free kicks in prime positions than they used to, so the average free kick is from further out.
It might also be that the knuckleball, while spectacular when it works, is simply less accurate than the curled technique, and the fashion for it has cost some goals in exchange for the ones it wins.
Which would be a very football thing to have happened — a technique adopted widely because the successes are memorable, at a slight net cost that nobody notices because the failures aren't.