The notion that different characters or pieces have different attributes seems to be one we take for granted today, but upon a quick historical survey, it is not so. After all, in chess, a pawn takes a queen or rook without any care for the latter's Constitution or Dexterity. Wargames such as Tactics used a combat results table rather than assign stats to individual units, which is something we even see in earlier editions of D&D (the weapons vs armours table).
Chainmail already had statistics such as armor class in '71 or '72, and obviously, the six attributes formed a key part of original Dungeons and Dragons in 1974.
Which RPG was the first to present stats as we know them today - a series of various attributes unique to an individual character? What inspired this system to present stats as it did?
For the purposes of this question, any statistic assigned specifically to a unit will do - "swordsmen have 5 hit points" or "mounted archers deal 7 damage" or "hobbits can carry 20 pounds of loot." I would also be interested in non-numeric attributes (as someone mentioned in the comments) as long as they fit the concept of stats and not lookup tables or similar.