This is from Dr Michael Heiser’s excellent and paradigm-opening book, The Unseen Realm. Small wonder James White was at odds with him, eh?)
The Calvinist view of God’s foreknowledge and predestination actually collapses into the conclusion: God knows everything about the future perfectly, because God controls everything deterministically. There is only ONE possible outcome with no alternatives, by definition there is a 100% chance to pick the right answer. It is literally impossible to guess wrongly about the future.
The Calvinist panelist Chris Date says as much from 12:30 onwards:
TBH this is a pretty lame kind of ‘omniscience’.
THE SCOTTTCAST 
August 19, 20 at 12:35 am
Yes!
Now lets unpackage the Calvinist’s rejection of Libertarian Freedom in favor of a world in which 100% is determined by an external mind.
What are the consequences of this in regard to the Calvinist’s ability to determine TRUE vs FALSE on any proposition?
His every perception of everything he examines was determined by an external mind. He is human, so he knows he has FALSE perceptions. And according to his doctrine, those FALSE perceptions would have had to have been infallibly decreed.
Now a FALSE perception – by definition – is a perception the person cannot know is FALSE, If he did know it was FALSE, then it would no longer be a FALSE perception. So for every Calvinist there exists a set of infallibly decreed FALSE perceptions.
We can then see Calvinist’s perceptions can be divided into two subsets:
1) FALSE perceptions – which the Calvinist is infallibly decreed to perceive as TRUE
2) TRUE perceptions – which the Calvinist is infallibly decreed to perceive as TRUE
Since he has FALSE perceptions which he is infallibly decreed to perceive as TRUE – it follows he cannot differentiate a FALSE perception from a TRUE perception.
Thus we can LOGICALLY conclude –
The Calvinist’s every perception of TRUE vs FALSE is 100% determined by an external mind.
It thus LOGICALLY follows – the Calvinist is bereft of any ability to determine TRUE from FALSE on any proposition.