The following year , he tied for first there with Robert HÃ 1\/4 bner and Viktor Korchnoi , playing several of his games while lying face-down on a table , having injured his back . The following year , he tied for first at the same event with Robert HÃ 1\/4 bner and Viktor Korchnoi , playing several of his games while lying face-down on a table , having injured his back .