Karpova: This game was extensively annotated (see source below), so just a few points:7...Nb4 <As in Löwy-Krejcik, Trebitsch Memorial, 1910.>
15...Ng4 <! Threatening 16...Bxe5 17.dxe5 Qb6+ winning the exchange.>
16.h3 <Insufficient. 16.f6 was very strong.>
27...Kg7 <Black feared 27...Kh8 28.Nxh7 Qxh7 29.Qf6+ Qg7 30.Qxf5, yet Georg Marco points out 28...Bd8! with advantage for Black.>
29...Kh6 <! Daing but correct.>
30.g4 <? Georg Marco considers this the losing mistake. Spielmann erroneously thought he would be winning. Marco suggests going for a draw with 30.Qh4+ instead.>
32.Nxd5 <Spielmann obviously thought that he would regain the piece. Now, 32.Qh4+ wasn't sufficient for a draw anymore (32...Kg7 33.Qe7+ Kg8 34.Nxd5 Qd6!.>
32...Qd6 <!>
38...Rd8 <Possibly even easier was 38...Re8 followed by e3, but Black now plays the rest of the game off the cuff.>
40...Kh4 <! Not 40...e3 41.Qf3+ followed by Qf8+ and draws.>
47...Rd2 <Not 47...Rf1+ 48.Kxf1 e2+ 49.Kg2 e1=Q 50.Qf6+ Bg5 51.Qd4+ and White wins. [Strongest was 47...Bh2+ 48.Kh1 e2 49.Qd4+ Kxh3]>
Source: Pages 120-123 of the May-June 1915 'Wiener Schachzeitung'