Bulls player Jimmy Butler turned down $40 million before the breakout season that's going to make him millions more

The fourth-year wing player has become one of the top two-way players in the NBA, averaging 20 points per game while guarding the opponent's best player nightly.

The timing couldn't have been better for Butler. On the eve of a contract year, Butler reportedly turned down a four-year, $40 million contract extension from the Bulls.

It was a risk at the time. Butler was coming off a season in which he played through injuries and his numbers suffered, posting woeful shooting percentages of 39% and 28% from three-point range. As always, turning down a contract means a player is betting on himself. Butler not only had to avoid injury this season, he had to outplay the $10 million a season he was offered.

Now Butler's gamble looks genius.As a fourth-year player, Butler can earn a maximum contract that's worth 25% of the salary cap, according to Larry Coon's CBA FAQ. With the salary cap projected at $67 million next season, if Butler gets a max contract, he can earn over $16 million next season. If he remains with the Bulls, they can also offer him a five-year contract (while other teams can only offer four) with 7.5% raises each season (while other teams can only offer 4.5%). If the Bulls offer him a maximum contract, Butler could earn ~$96 million over five seasons — more than double his extension at the beginning of the year.