Board Thread:Naruto Discussions/@comment-3965545-20160202201023/@comment-3965545-20160203081714

Because if his reserves truly were like that while not sick, then why would his edo Tensei be able to start using Susanoo the same as Sasuke does although he does not have EMS?? His reserves would be the same as his nonsick self, only refilling after every expenditure infinitely.. therefor his limits of usage would of still been the same as his healthy life. He showed he was able to do MORE so therefore in health he could do more. That's why I say 2.5 which is even lower than Kakashi, is only for his sick state. Besides the stats taken in DB3 are only accounting for his battles he had in P2 so they only truly account for his battle with Sasuke. Stats only account for battles shown for the most part as Databook 1 specified.

DB1 says all stats are evaluated by characters current performance.

https://forums.animesuki.com/showthread.php?t=13632

So Itachi's stats are about his sick state none the less. Databook's explanation of the stat key and stats themselves says so, and also says they are prone to change.