At the beginning of his book, "How life imitates chess," Garry Kasparov gives a fascinating account of his dramatic world title match with champion Anatoly Karpov.
He was 21 years old and had risen to the top of the chess world with such speed that he could not imagine this final hurdle could block his way.
"Up to that point in my career," Kasparov wrote, "everything had become easily for me, winning had become the natural state of things." The young challenger, however, soon found himself on the brink of defeat.
An incredible 17 games followed without a decisive result. "The match dragged on month after month, breaking every record for the duration of a world championship match," Kasparov recalled.
During hundreds of hours of play and preparation, he had to focus on his decision-making to fix whatever was going wrong.
However, when he lost the 27th game to go down five-nil it seemed he wasn't learning fast enough to save the match. One more loss and it would be three long years before he could hope for another shot at the title.
"As the match entered its third month, I stayed in my defensive crouch," Kasparov related. "I wasn't winning but the change in style had made things much tougher for Karpov. I felt I was getting closer to solving the puzzle while, at the same time, my opponent was becoming more frustrated and tired.
"At last the dam broke. After surviving game 31, in which Karpov failed to land a decisive blow, I won game 32 and went on the offensive. Meanwhile the world began to wonder if the match would ever end. No championship match had ever gone beyond three months, and here we were entering the fifth. Karpov looked exhausted and I started to press harder.
"After coming close to winning game 46, I won game 47 in crushing style. Could there be a miracle? Exactly at that moment the organisers decided the players needed a break, and the next game was postponed for several days. Despite this unprecedented decision, I also won the next game. Suddenly it was 3-5 and the momentum was on my side.
"Then, in a bizarre twist on February 15, 1985 in Moscow, the International Chess Federation, FIDE, responding to pressure from the Soviet sport authorities, called a press conference to declare that the match was cancelled.
After five months, 48 games, and thousands of play and study, the match was over without a winner.
"We would have to return six months later to do battle again, and next time there would be a limit of 24 games. Karpov was removed from immediate danger and could be content that he would hold on to his title a while longer."
Kasparov said he learned "a huge amount" from this long and gruelling "tutorial." In fact, he added, the world champion had been his personal trainer for five relentless months.
"Not only had I learned the way he played, I was now deeply in touch with my own thought processes," the challenger noted.
"I was increasingly able to identify my mistakes and analyse why I made them. From that process I learned how best to avoid making them again, to improve the decision-making process itself. This was my first experience in questioning myself instead of relying only on my instincts."
Kasparov acknowledged that the champion knew he would consistently give up material for attacking chances and used this habit against him in the first match. Only when he began to rein in that instinct did he begin to put up effective resistance.
When the second match got under way in Moscow, Kasparov did not have to wait months for his first win; he won the very first game. The match was still a tough fight–he trailed for most of the early stages–but this time he wasn't the same innocent 21-year old.
"I had patched the holes Karpov had so successfully exploited at the start of the first match. Now a savvy veteran at 22, I became world champion and went on to hold the title for 15 years.
"When I retired in 2000, I was still the highest-rated player in the world, but for a chess player 41 years old. Still, I remained at the summit for nearly two decades, while many of my opponents were in their teens."