User blog comment:Leyrann/Hard counters./@comment-89.177.72.8-20120728003240/@comment-89.246.12.190-20120728121915

"Attack speed reductions stack multiplicatively, and take percentages off the final attack speed value after all bonus attack speed has been factored in." <- from wiki http://leagueoflegends.wikia.com/wiki/Attack_speed

so with out AS items Fiora has (lvl 18) no runes/masteries with AS too: 1,015

with Burst of Speed: 1,821 now crippled by Malph: 0,728

it's better to w8 till the AS slow is over

Formula: ( base AS * ( 1 + AS% ) ) * ( 1 - AS Reduction )

AS%: AS% per lvl, from items, runes, masteries, buffs, skills (per lvl happens first on lvl 2-> at 18 only 17*AS/lvl)

AS Reduction: only one AS slow so it is 60%

AS = ( 0,672 * ( 1 + 17 * 3% + 120% ) ) * ( 1 - 60% )