R.C. Sproul & Middle Knowledge

In the following quote, Calvinist R.C. Sproul, in his book, What is Reformed Theology?, seems to indicate that Reformed Theology professes belief in "Middle Knowledge," and uses the illustration of a "Chess Master." However, it appears that Sproul makes this acknowledgement with the caveat that perhaps God decrees all contingenies, which I find a bit odd, and so I would like to get your take on the matter.

R.C. Sproul writes: "God's omniscience refers to God's total knowledge of all things actual and potential. God knows not only all that is, but everything that possibly could be. The expert chess player exemplifies a kind of omniscience, though it is limited to the options of chess play. He knows that his opponent can make move A, B, C, or D, and so forth. Each possible move opens up certain counter-moves. The more moves ahead the expert can consider, the more he can control his chess-game destiny. The more options and counter-options one considers, the more complex and difficult the reasoning. In reality no chess player is omniscient. God knows not only all available options, but also which option will be exercised. He knows the end from the beginning. God's omniscience excludes both ignorance and learning. If there is ignorance in the mind of God, then divine omniscience is a hollow, indeed fraudulent, phrase. Learning always presupposes a certain level of ignorance. One simply cannot learn what one already knows. There is no learning curve for God. Since no gaps exist in his knowledge, there is nothing for him to learn. For us to know what will happen tomorrow, we must guess concerning things that are contingent. If I say to a friend, 'What are you going to do tomorrow?' he might reply, 'That depends.' Those two words acknowledge that there are contingencies ahead and that what happens to us depends on these contingencies. It is said that God knows all contingencies, but none of them contingently. God never says to himself, 'That depends.' Nothing is contingent to him. He knows all things that will happen because he ordains everything that does happen. This is crucial to our understanding of God's omniscience. He does not know what will happen by virtue of exceedingly good guesswork about future events. He knows it with certainty because he has decreed it." (What is Reformed Theology?, pp.171-172)

So are we to conclude from R.C. Sproul that God knows all contingencies because He has decreed all contingencies? How would that make sense? Apply that logic to Matthew 11:20-24, and should we conclude that God decreed that if Tyre and Sidon had seen the Lord's miracles, that they would have believed? Unfortunately, Sproul does not come right out and say that God decreed all contingencies, or how God would decree undetermined events.

(Next week, we'll examine the quote by R.C. Sproul that states that there is essentially no difference between a non-Calvinist and a Pelagian. He calls it "a difference without a difference." The following week, I want to examine "Compatibilism." Currently, I have a post on CARM regarding an excerpt from "Debating Calvinist" that I will repost here for follow-up discussion. http://www.christiandiscussionforums.org/v/showthread.php?t=116338)