It's one of the most beloved household board games – regardless of the ferocious arguments it causes at Christmas. 

Now, scientists reveal the secret to beating friends and family at Guess Who?, the classic two-player game accompanied by the satisfying sound of snapping plastic. 

Dr David Stewart, mathematician at the University of Manchester, says the trick is to always ask a question that splits your suspects 'as close as possible into halves'.

That's because you don't want to risk asking a question that only eliminates a tiny minority of the suspects. 

Since the game was released back in 1979, players have asked generic questions like 'Do they have a hat?' to guess their opponent's character. 

But instead asking about their hair colour or attire, you might want to be more precise with your inquiries. 

Dr Stewart told the Daily Mail: 'You can always ask a question that captures the exact number you want in the ‘yes’ category.

'Use a formulation like: "Does their name come before 'Nancy' alphabetically?"' 

In Guess Who?, players have to guess their opponent's chosen character by asking yes-or-no questions. In this game, the player with the blue board has picked Claire as their character

The format of Guess Who? is simple: each player has a board that features cartoon images of 24 people with names, including Bernard, Eric and Maria. 

They also have a card picked from random that features one of these characters – which the other player has to guess the identity of. 

The two players take turns to guess the identity of the other's chosen character by asking yes-or-no questions, such as 'are they wearing a hat?' or 'do they have a moustache?' 

For example, if player 1 asks 'do they have brown hair?' and player 2 answers 'yes', player 1 knows to eliminate the characters that don't have brown hair. 

The researchers explain: 'Upon eliminating characters, one flips down those characters’ image on one’s board. Each player knows how many the other has left, but not their names.'

The winner is simply the first person to correctly identify their opponent's chosen character (but if both players correctly identify their opposition’s character in the same amount of moves it’s a draw). 

A question you should never ask early on would be 'Is your person wearing glasses?' because there's actually only five glasses-wearers on the whole board – and this is the mistake many players make.

However, it may be an acceptable question later in the game if you have, for example, four suspects left on the board with glasses and four without. 

Guess Who? was developed by Israeli game inventors and first released in Dutch in 1979 under the name 'Wie is het?'. Milton Bradley then produced the game in the UK before it was brought to the US in 1982. It is now owned by Hasbro