At the time, Moby thought long and hard about how he was supposed to complete the quest that Avilia gave him.
To him, at first, it seemed impossible but after thinking long and hard he noticed many things that he could use to his advantage in order to complete the quest.
The first was what the quest itself was asking from him. It did not ask him to win the fight but to instead win the bet which was much more doable in his eyes and gave him hope that it could be completed.
After that, Moby thought long and hard thinking of many different factors in order to make sure that there was the lowest chance of failure.