While it seems plausible that Backgammon took its name from the newly invented triple win, made when the loser is "backward in the game", or "backgammoned", there can be no doubt that the meaning of the word is literally "back game".
The sometimes-encountered suggestion that it derives from Welsh roots including "bach" (little) is as ludicrous as the derivation of "penguin" from Welsh "pen gwyn" (white head). "Gammon" may recall a side of bacon, but is more reliably interpreted as a typical piece of seventeenth-century happy-go-lucky spelling, in this case of "gamen", the older form of "game". By a later development, the increased win for a final doublet was abolished; the original backgammon (triple) was reduced to a double and renamed a simple gammon; and the backgammon triple win redefined into its present form.
The idea of degrees of win was not in itself entirely new. Earlier varieties of Tables included a double win or "lurch" made before the opponent had borne off any men. As this has been interpreted by some as an error arising from confusion with Cribbage, perhaps we should remember that it has already been encountered in the reference (above) to the Long Game, Ludus Anglicorum. (It ultimately derives, via French, from a German word meaning left-handed, or perhaps more appropriately "wrong-footed".)
Backgammon vied to some extent with its immediate forerunner, as suggested by this reference to it by a letter-writer of 1645:
"Though you have learnt to play at Baggammon, you must not forget Irish, which is a more solid and serious game".
Several games "within the tables" still played in the seventeenth century are described in three contemporary sources, namely Charles Cotton's Compleat Gamester of 1674, Francis Willughby's Book of Plaies ("Book of Games") of about the same date, consisting of hand-written entries in a large notebook compiled over several years, and Randle Holme's Academy of Armory of 1688.
In addition, Thomas Hyde wrote (in Latin) a history of board games with particular attention to "Nerdiludus" - the game of Nard presumably for nerds - but concentrates more on the language and literature of the subject than on the actual rules of play.