In section LXXII of Mahabharata, there is an excerpt regarding the science of dice.
"Vrihadaswa said, '.......Rituparna said, 'O Vahuka, thou art the only charioteer, there is none other in this world. And, O thou versed in horse lore, it is through thy help that I expect to go to the Vidarbhas. I place myself in thy hands. It behoveth thee not to cause any obstacle. And, O Vahuka, whatever thy wish. I will grant it if taking me to the country of the Vidarbhas to-day, thou makest me see the sun rise.' At this, Vahuka answered him, saying, 'After having counted (the leaves and fruits of the) Vibhitaka, I shall proceed to Vidarbha, do thou agree to my words. Then the king reluctantly told him, 'Count. And on counting the leaves and fruits of a portion of this branch, thou wilt be satisfied of the truth of my assertion.' And thereupon Vahuka speedily alighted from the car, and felled that tree. And struck with amazement upon finding the fruits, after calculation, to be what the king had said, he addressed the king, saying, 'O monarch, this thy power is wonderful. I desire, O prince, to know the art by which thou hast ascertained all this.' And at this king, intent upon proceeding speedily, said unto Vahuka. 'Know that I am proficient at dice besides being versed in numbers. And Vahuka said unto him, 'Impart unto me this knowledge and, O bull among men, take from me my knowledge of horses.' And king Rituparna, having regard to the importance of the act that depended upon Vahuka's good-will, and tempted also by the horse-lore (that his charioteer possessed), said, 'So be it.' As solicited by thee, receive this science of dice from me, and, O Vahuka, let my equine science remain with thee in trust.' And saying this, Rituparna imparted unto Nala the science (he desired). And Nala upon becoming acquainted with the science of dice, Kali came out of his body, incessantly vomiting from his mouth the virulent poison of Karkotaka.
With the help of that science, Rituparna can exactly calculated number of leaves, fruits etc., From Rituparna, Nala also got the science of dice. Vrihadaswa gave it to Yudhisthira.
In this context, I have two doubts:
1) Along with these four people ( Rituparna, Nala, Vrihadaswa, Yudhisthira), are there any other people who know this science of dice in ancient scriptures. If yes, list out them.
2) Is there any text available explaining the science of dice in detail?