The Schliemann goes down again

The Schliemann Variation of the Ruy Lopez has always danced along the edge of the sound/unsound cliff. It has bursts of popularity at the GM level before heading back into 'not quite refuted' territory, where unpopular openings languish.
Recently it became popular again, even at the 2700+ level, although this is also a mixed blessing. While players of the Black pieces are happy to wheel it out, the main reply for White seems to be the boring 4.d3 While this is not a clear cut attempt to refute the opening, it is an attempt to draw its teeth, and create positions that a Schliemann player might not enjoy so much.
A very recent example of this occurred in the current US Championship, in a game between Sam Shankland and Timur Gareev. White played 4.d3 and then took aim at various weaknesses in Black's position. To his credit Black did get an attack going, but White 'turtled' before fighting back to reach a won ending.


Shankland,Samuel L (2661) - Gareev,Timur (2604) [C63]
US Championships 2015 St Louis, MO (7.6), 08.04.2015