**TYPE OF BUG**:
The problem of the NaN value is get from the function **Riot.DDragon.fn.calcAspd** because you pass in **Riot.DDragon.fn.init** the _stats.attackspeedoffset_ as _undefined_.
I saw that no one of the champion in the https://ddragon.leagueoflegends.com/cdn/9.6.1/data/it_IT/champion.json has the property _attackspeedoffset_.
I searched in some old json and I found it was present, so i think this is a typo.
Hope to be helpful,