http://Pokemondb.net/pokebase/91472/what-is-the-%-of-a-move-to-fail-with-100-accuracy I read the answer, and I know it to be correct. But my Ivysaur used Tackle last night, and I missed with no accuracy and evasion modifiers. This is in LeafGreen.
Tackle's accuracy in Gen III was 95. You were just unlucky.
Source: Bulbapedia