It seems like on goal kicks, other free kicks, and throw-ins, 9 out of 10 times a defender will be on the spot and get to the ball before the team kicking/throwing in the ball does. It makes goal kicks and throw-ins practically guaranteed turnovers.
Why do defenders appear to have an inherent advantage on long balls?
Probably a few factors -
The defenders are facing the ball so can attack it in the direction they are playing, so they usually have a better view, can position themselves better against a forward, say, who might be running backwards.
The forward has a far harder job trying to win the ball and get it under control, or at least make a controlled pass, than the defender who just needs to win the challenge. There are usually more defenders than oppostion attackers around a long ball, so the attacker is being asked to make a demanding, skillful play whereas the defender might just need to get their head on it and it will probably drop to a teammate.
Defenders are usually taller, bigger and stronger than attackers so it’s hard to win an aerial duel. The type of centre forward who is also big, strong, aggressive and great in the air certainly exists, but is largely out of fashion because finding someone like this who can also play football and is not slow is really difficult. Plus football in general is a lot more skillful than it used to be (at least in England) so that long ball, percentage style isn’t in vogue. You’ll see it at times when team’s are desperate but no one really sets out to play that sort of football nowadays as a philosophy.
A hard centre forward who can hold-up play is great to see, IMHO - make the ball stick up top. Few have the physical tools and skill to do this effectively, but other dimensions of attacking play are more valuable these days.
Like with deep American Football passes and two line Hockey passes, the defender’s job is simply a lot easier. Essentially all they really need to do is prevent the forward from doing what they are trying to do. Because they usually have the numbers, simply redirecting the ball or getting in the way is more than enough. The forward on the other hand usually needs to receive the ball in such a way that they can make a move, make a pass or otherwise evade someone. This is high skill stuff. In purely physical terms, it’s easier to get yourself in front of a moving object than it is to try and match the ball trajectory in the same direction.
Generally speaking, there are more players who are doing a defensive job usually than there are attacking. Remember; no one has to guard the person taking the restart. In a typical soccer formation, there are 4 or 5 players who are tasked with defending the last line, and another 2 or 3 players who are tasked with defensive activities in the middle of the attacking end of the field. By comparison, most teams have a total of 5 or 6 players who are tasked with primarily attacking duties.
Now, contrary to your characterization of throw-ins, in professional soccer the throw in is controlled by the team throwing the ball about 75% of the time or more. Obviously, this goes down the farther the ball is thrown.
On long restarts that are launched downfield, the attacking team often doesn’t even try to get to the ball first. Rather, they simply contend for the ball, and try to control the ball after it is played (usually by a head) by the defending team.
To add to the other responses - although defenders may win the first header a large percentage of the time, it’s not a “guaranteed turnover” because a lot of the time, they will be simply heading the ball back to the opposition.
I strongly doubt your experience accurately reflects top level soccer stats. A lot of goal kicks, free kicks and throw-ins are short and perfectly aimed at an open team mate. Of the ones that are longer and intended as more of an directly offensive play, a lot more than 9 out of ten reach the intended target, even if they may be fighting for it.
Even for the really long, basically wild ball, set pieces I doubt it’s 9/10 to an opposing player.
I think you’re overcounting the turnovers because throwing straight to a team mate and continuing play is basically unremarkable.
I may by wrong though, so since I can’t find any easily googleable stats I’m going to make my own tiny dataset.
Here’s a very small amount of real data:
In the fifteen first minutes of a random Real Madrid - Barcelona match, I counted:
6 throw-ins, of which only one went to an opponent. Five of the throws were short and the one long one was lost to an opponent quickly.
3 free kicks, all of them short, all of them straight to a teammate.
4 goal kicks all of them straight to a teammate, although three of those were off camera while replays of the previous attack were happening and I could be mistaken.
In the fifteen first minutes of a random Norwegian 2. tier league match:
7 throw-ins, only two went to an opponent, and those were the ones that were thrown into the crowded box. (Where I couldn’t actually see what happened, so I counted them as received by opponent.)
8 free kicks, 3 went to an opponent, they were also the only ones aimed long at a running attacker.
4 long goal kicks, all of them straight to a teammate.