You had a lot of faith in your skills as a gambler, although skills meant nothing here. Even if nobody could detect it, D'arby was a cheat to the very bone and incapable of a clean game. So, even though you were close to victory, nothing could have brought it to you unless you had realized.

He chuckles to himself, looking down at the chips. "Hm, I suppose I could take your soul as we bargained..." He trails off, eyes narrowing. "Though, I've thought of something far more interesting. Instead, we could agree that I've won you."