MANILA, Philippines -- Grandmaster Wesley So failed to cash in on a pawn and positional edge and settled for a gruelling 80-move draw with the United States' GM Fabiano Caruana in their Guioco Piano game to remain half a game behind the three-man lead pack after six rounds of the Tata Steel Chess Masters in Wijk aan Zee, The Netherlands Friday night.
So outplayed Caruana in the opening to gain a positional advantage and later a pawn but Caruana fought back strong and forced a split after the two ended up with a pawn and a king.
It was So's sixth straight draw after he downed Dutch GM Anish Giri in the opening round that put him in a three-way logjam at No. 4 with reigning women's world champion GM Hou Yifan of China and Ukrainian GM Pavel Eljanov with 3.5 points each.
They're half a point behind Caruana, Chinese GM Ding Liren and top seed and reigning men's world champion GM Magnus Carlsen of Norway.
Ding split the point with GM David Navarra of the Czech Republic while Carlsen posted his second straight win after downing Russian GM Yevgeny Tomashevski to catch up with the leaders with four points apiece.
So was playing Chinese teenage phenom GM Wei Yi in the seventh round at press time.