I would like to know counter arguments as well, if any.
Chaturanga is the ancient game that gave birth to board games chess, shogi, makruk, xiangqi and janggi. I believe Chaturanga is the same game as Shatranj or got only slightly varied while moved from India to Sassanid Persia. There is another variation of chess Chaturaji which used 2 dices and 4 players (Ludo style) around 11th century or slightly earlier. The game of chess evolved from Shatranj and got most of the current rules around 15th century in Spain. It was only at late 19th century that Chess as we know of has been formalized.
I found this article very informative: http://www.saudiaramcoworld.com/issue/200904/the.game.of.kings.htm
These sections were particularly relevant:
Chess, however, was not invented in Persia. All early Persian references to chess use the term chatrang, from the Sanskrit chaturanga (“in four parts”), which describes the four components of an early Indian army: infantry, cavalry, elephants and chariots. The use of a Sanskrit-derived word for chess in an early Persian romance suggests an Indian origin for the game and not local invention, although supporting evidence is murky.
... The only convincing early Indian mention of chess is in a romance attributed to the sixth century, thus slightly earlier than the first Persian and Central Asian evidence. The poet Subandhu used a chess image to describe the monsoon season:
The time of the rains played its game with frogs for chessmen which, yellow and green in color … leapt up on the black field squares.
A story of the seventh-century Persian king Nushirvan (recorded by Firdawsi in the 11th-century Shahnamah, or Book of Kings) also supports an Indian origin of chess. An envoy came from India, the story says, “with elephants, parasols, and cavalry” and a chessboard, chessmen and a challenge: If Nushirvan’s courtiers could figure out the basic rules of the game, then unknown in Persia, the Indian king would gladly pay tribute to the Persian monarch. If they failed, however, Nushirvan would pay tribute to the Indian king. Nobles and priests labored without success for a week. Finally, after a day and a night of struggle, Nushirvan’s vizier deciphered and described the game:
The sage has invented a battlefield, in the midst of which the king takes up his station. To the left and right of him the army is disposed, the foot-soldiers occupying the rank in front. At the king’s side stands his sagacious counselor, advising him on the strategy to be carried out during the battle. In the two directions the elephants are posted with their faces turned toward the conflict. Beyond them are stationed the war-horses, on which are mounted two resourceful riders, and fighting alongside them to the left and right are turrets ready for the fray