People are often looking for an answer to their ‘repertoire problems’ and can be delighted when they discover something simple to play, such as the London System. But after a while a new problem can occur, that of stagnation. They’ve reached a point where they know what they’re doing but the mind is no longer being engaged. This means that it’s time for a change.
For this very reason Bent Larsen used to like to change his openings every couple of years, it helped keep him interested. And it also helped him take his opponents off guard when they were expecting him to play something else.
Boris Ivkov once had to prepare for Larsen in a match and spent a many hours studying one of Larsen’s favorites, Bird’s Opening. Unfortunately for him Larsen didn’t play it, but rather than let all this hard work go to waste he decided to play it himself.
It’s interesting that Larsen not only kept himself fresh but helped Ivkov to do so too: