Imagine this hypothetical situation.
It's Starly versus Ponyta. Current stats:
Starly = +0 Atk, +0 Def
Ponyta = +0 Atk, +0 Def
Starly uses Growl and Ponyta uses Tail Whip. Current stats:
Starly = +0 Atk, -1 Def
Ponyta = -1 Atk, =0 Def
Ponyta uses Tackle on Starly.
If Ponyta is at -1 Attack, and Starly is at -1 Defence, will her Tackle deal the same amount of damage as if they were at +0 Attack and +0 Defence, respectively?