The story is told with a long flashback, so the banker's changes in his feelings and thoughts about the bet are not described in any chronological development. We know mainly how he feels about the bet just before the lawyer's fifteen-years of solitary confinement are about to end. The story opens on the night before the lawyer will be free to leave his confinement and free to collect the two million rubles.
It was a dark autumn night. The old banker was walking up and down his study and remembering how, fifteen years before, he had given a party one autumn evening.
By this point in time the banker's attitude has changed completely. He bitterly regrets having made the bet, partly because he thinks it is going to cost him two million rubles, partly because the outcome proves nothing, and partly because he believes the two men were terribly foolish to have made such a bet in the first place.
And this wild, senseless bet was carried out! The banker, spoilt and frivolous, with millions beyond his reckoning, was delighted at the bet.....And now the banker, walking to and fro, remembered all this, and asked himself: "What was the object of that bet? What is the good of that man's losing fifteen years of his life and my throwing away two million? Can it prove that the death penalty is better or worse than imprisonment for life? No, no. It was all nonsensical and meaningless. On my part it was the caprice of a pampered man, and on his part simple greed for money...."
The narrator does not tell us how the banker's attitude evolved over the years. Only that he was amused and delighted when the bet was first made and that he is suffering mental agony at the end of the fifteen years. After the men make the bet, the story focuses on what the lawyer appears to be doing in his self-imposed captivity. Presumably the banker begins to feel a little bit worried when the lawyer does not give up and sacrifice the two million rubles after he has been imprisoned for longer than the banker expected he would be able to stand it.
"Think better of it, young man, while there is still time. To me two million is a trifle, but you are losing three or four of the best years of your life. I say three or four, because you won't stay longer."
The reader starts off with the knowledge that the lawyer was indeed able to stand it, not only for three or four years, but for the full fifteen years. But the reader's interest is held by the question of how the lawyer was able to stand it. Perhaps the reader wonders whether he would be able to stand such an ordeal himself and, if so, what he would do to get through his long, solitary days and how he could keep himself from going insane.
We can imagine that the banker's attitude over the years changes from confidence and amusement, to doubt, amazement, concern, fear, dread, and finally to desperation. Perhaps he loses a lot of his capital because his prisoner's endurance has made him anxious and caused him to lose his nerve. In other words, perhaps he becomes afraid to make other bets, which is what his and all speculations on the stock market really amount to. He was confident he would win the bet with the lawyer because he had confidence in his judgement, but the lawyer's adjustment to solitary captivity has made the banker lose his self-confidence, and that loss of self-confidence has adversely affected his ability to play the market successfully.
Fifteen years before, his millions had been beyond his reckoning; now he was afraid to ask himself which were greater, his debts or his assets. Desperate gambling on the Stock Exchange, wild speculation and the excitability which he could not get over even in advancing years, had by degrees led to the decline of his fortune and the proud, fearless, self-confident millionaire had become a banker of middling rank, trembling at every rise and fall in his investments.