visayanbraindoctor: The attacking Keres at his best in another Sicilian massacre.
At move 12, all of White's major and minor pieces are on the 1st and 2nd ranks, and Black's Kingside pawn structure remains intact. Who would have the tactical and attacking vision to conjure a sudden attack on the Black King?
13. d5 initiates a series of tactics that gives White a definitive advantage based on opening up the a1-h8 diagonal. Keres must have already expected Folty's reply 13... Na5, which attacks his c4 pawn while defending the b7 bishop from a discovered attack (dxe6).
14. Nf4! is the bolt from the blue. It turns out that Keres was not interested in his Queenside or his hanging center but in a direct attack on the Black King apparently conjured out of nowhere, as evidenced by his next move 15. Bg7. All his previous moves since 13. d5 are all about opening lines of attack to the Black King.
There were other ways for White to play the middlegame, but I believe this type of attack is something that the young Keres would hardly miss, even though it obviously takes a very good chess imagination to think up of such a whirlwind of tactics and King hunt attack from a position at move 12 wherein all one's major and minor pieces are on the 1st and 2nd ranks. Even granted that the rattled Foltys could not find the best defense; that does not take away my awe at Keres' tactical and attacking vision.
There is a popular theory that Keres played poorly in the Nazi sponsored tournaments of WW2. After going through his games, my strong opinion is that it's totally wrong. Keres was playing vigorously and brilliantly. In fact, I think he was at his high plateau in the 1937 to 1943 period and hit his peak around 1943.
After the Soviets annexed Estonia, I get the feeling the Keres stopped playing inspired chess. His games just seemed less aggressive.