His conjecture was better than mine.

Guess : estimate or conclude (something) without sufficient information to be sure of being correct.
Knowledge : facts, information, and skills acquired through experience or education; the theoretical or practical understanding of a subject.
Intuition : the ability to understand something instinctively, without the need for conscious reasoning.
Experience : practical contact with and observation of facts or events.
Conjecture : an opinion or conclusion formed on the basis of incomplete information.

Synonym of Conjecture is Guess