This week, two of the mightiest figures in the world of chess will clash in a 25th-anniversary replay of their championship match that was abandoned, with no clear winner, after a marathon five-month battle of skill and wit.

Russians Anatoli Karpov, 58, and Garry Kasparov, 46, are making final preparations for the exhibition showdown in Valencia, Spain, with warm up rounds due to begin today.

The two players still do not speak to each other. Such is their rivalry that the opponents have insisted they stay in separate hotels before the 12-game match begins.

They are, as Kasparov once described, like “fire and ice.”

While Karpov promotes a slow method of positional strangulation on the chess board, Kasparov favours more spectacular tactics.

Karpov was a defender of the Communist regime while Kasparov has been described as an aggressive and rebellious political agitator, who later became a vocal opponent of Russian President Vladimir Putin.

Karpov is holed up in the highest apartment block available on the Valencian coastline after making a special request for sky-high accommodation. He is there to wrap up his ambitious training regime with a team of world-class mentors.

Kasparov is under the wing of his mother Clara, who instilled a love of chess in her son as a young boy and who travels with him to all major tournaments.

The chess player took her surname after the death of his father and, to commentators, her presence signals the importance of the match to Kasparov.

The original 1984 meeting between the two was controversially abandoned by match officials on health grounds, after both players lost weight during the strenuous fixture.

It ended despite protests from the rivals, who wanted to continue the closely fought contest. Karpov had raced to a 4-0 lead after nine games in a “first to six wins” match, but Kasparov battled back, drawing the next 17. He then closed the gap to 5-3.

It was at the rematch the following year that he knocked Karpov off his world throne, where he had sat for 10 years, and made Kasparov the game’s youngest ever world No 1, aged just 22.

Kasparov has been training with his prodigy Magnus Carlsen, the 18-year-old Norwegian who became a Grand Master at just 13, to prepare for the semi-rapid and blitz games this week.

By contrast to their 1984 encounter, the match will carry a strict five-day time limit.

Kasparov said: “In this case, nostalgia will be a positive thing, and the duel will serve to put a spotlight on chess again, just like 25 years ago. In any case, we’re both capable of playing high-quality chess.

“As well as being the most important rival in my sporting career, [Karpov] is my grand master, from whom I have learned the most, as much in chess as in life.”

The chess giants, now in semi-retirement, have played each other in a record 144 games, including 40 drawn games in their world title bout between September 1984 and February 1985. They last played each other in 2002.

Kasparov was arrested during an anti-Kremlin protest in 2007 as he prepared to stand against President Putin in the 2008 elections.

Karpov tried to visit him in his cell “as a gesture of respect, not of friendship.” He has since joined the Public Chamber of Russia, which scrutinises the role of parliament and government, and has involved himself in several humanitarian causes.

Valencia promotes itself as “the cradle of modern chess.” It is here, it is claimed, that resident Francesch Vincent published the first book containing the modern chess rules, in May 1495.