It’s not a novelty, but it’s new on the highest level. Kramnik’s approach is probably the easiest way to get a technical position in the Marshall Gambit. It is not clear though if this was a bluff or his secondary repertoire. Nevertheless Kramnik is in such a slump that he must be regarded as the target. Caruana missed a golden chance.
Caruana leads the field by half a point and has to play Karjakin (black), Aronian (white) and Grischuk (black). Meanwhile Mamedyarov will face Ding (white), Grischuk (white) and Kramnik (black). In my opinion a tiebreak is the most likely outcome.