“Handles the ball deliberately,” is the phrase in the Laws of the Game, which offer no further explanation. At first glance it seems like we don’t need any. However this is the only place in the laws where referees are expected to judge deliberateness, and in practice footballers, fans and pundits still argue constantly - and understandably - about handballs.
Say an attacker has the ball and a defender deliberately puts their hand where they think the ball is most likely to be kicked. Is there anything wrong with that in itself? You can put your hand where you like. If the attacker then kicks the ball into your hand so hard that you can’t avoid handling, that can hardly be a deliberate handball.
Or can it? The defender has not “handled the ball deliberately”, but they have deliberately made an accidental handball more likely to happen. They’ve handled half-deliberately, you might say. Goalkeepers routinely get credit for this, not for pulling off saves exactly, but for managing to be in the right place when the ball hits them. If a defender stood like a goalkeeper, arms spread wide in front of the attacker’s target, they should surely be penalised if the ball hits their hand. They have deliberately sought advantage from a handball, after all, even if they haven’t deliberately handled it.
In an attempt to solve this problem, referees are advised by the International Football Association Board to consider whether a player’s hand is “in an unnatural position” - implying that the player is responsible for anything that results from their hand being where it didn’t have to be. But this creates problems too, even if you could define what all the natural and unnatural positions were. A player could have their hand in an unnatural position for innocent reasons after all. They might be gesticulating to a teammate when the ball hits their hand. They might be lifting their arms to jump, certainly a deliberate movement, but not intended to cause handball.
Gary Lineker has argued that a handball should be given whenever the ball strikes a player’s hand, regardless of intent. This would certainly make the rule clear, but it would also lead to players aiming for defenders’ hands in the penalty area rather than trying to beat them, which is less fun to watch and even more unfair. Instead, it seems to me, we must begin by accepting that a grey area of half-deliberate handballs exists - like manslaughter in comparison with murder. Deciding what has happened must be a matter for the referee’s judgement, but referees should be allowed to penalise this half-deliberate handballs with indirect free kicks, meaning they need not lead to penalties, and will stop being so inflammatory.