Our research shown that moves do not have a variable dodge window. Instead, dodging is binary: either you take full damage of the attack, or receive a 75% damage reduction from a successful dodge.
The only thing that matters is time your dodge just after the yellow flash from each defender attack.
As such, we removed the dodge window information from GamePress to avoid further confusion. See the new gym mechanics page for more details:
http://pokemongo.gamepress.gg/gym-combat-mechanics