In Generation I, there were only four IVs stored for each individual Pokémon: Attack, Defense, Speed, and Special. Each of these covered the respective stat, with the HP IV determined from the IVs stored for the other four. IVs had a range from 0-15, in binary 0000-1111, with the HP IV taking the final binary digit of the Attack, Defense, Speed, and Special IVs and placing it, in that order, for its own IV. As such, a Pokémon with an odd-number Attack IV had 8 added to its HP IV, Defense had 4 added, Speed had 2 added, and Special had 1 added.