Pawn and Two: <Sem> In the tournament book, Steinitz called 23...Nh5!, <A first-class move...>.Fritz indicates 23...Nh5! is Black's strongest move. Fritz provided the following continuations as best after 23...Nh5!: (-2.75) (22 ply) 24.gxh5 gxh5 25.Rg1 Bxh2 26.Kxh2 Rf3; or (-4.31) (22 ply) 24.Bd1 Qd6 25.Rh1 Nf4+ 26.Kg1 Qf6 27.Nf3 Nd3; or (-4.91) (22 ply) 24.Rh1 Nf4+ 25.Kg1 Nd3 26.Rf1 Bf4 27.Qe2 Qd6 28.g5 Bg3 29.f4 Bxf4. Black is winning in all of these continuations.
Accepting the knight sacrifice, 24.gxh5, was White's best option, but his weaknesses on the h2/b8, & h3/c8 diagonals, and on the f-file, made his position untenable.
While Fritz preferred 24...gxh5, Showalter's 24...Bxh2 was also winning, and was stronger than Steinitz's recommendation of 24...Bf4.