Of that He wishes to control. Omnipotent includes God granting man free will. This does not affect omniscience or foreknowledge. This is the aspect that Calvinists often conflate and confuse.
But we are saved by faith through Jesus Christ our Lord. Who God grants this faith to is impossible to tell.
IOW: We're saved unknown and for unknowable reasons.
There are only two types of wills; God's will and man's will. God's will=good. Man's will=bad. I don't see what is confusing about that. In fact, I find Calvinist rather simple to understand. Man has the same nature, man makes same bad choices, God saves men in the same way, etc.
What I find confusing is people saying:
IOW: We're saved unknown and for unknowable reasons.
Not quite. We do know we are called according to His purpose to bear fruit to bring glory to God. Every Christian does this in some form or fashion. How we bear fruit is not always known.