www.youtube.com/watch?v=nOvUqQCJJYQGM Jon Speelman reviews round 5 of the Sinquefield Cup 2019.
It seems Naka's widely criticized 57..., b4 wasn't a mistake at all and well within the draw margin. The real mistake was 60..., Ba3? where fxe4, Kxe4, Bd2 was holding.
For instance 60..., fxe4 61. Kxe4, Bd2 62. f5+, Kf7 63. Kd5, Be1 64. Kc4, Ke7 65. Bd4, Kf7 66. Bc5, Kf6 67. Bxb4, Bh4! 68. Bc3+, Kxf5 and now b4, Ke6 or Kd5, Be7 etc.