Modern Chess, Opening Databases, 2020.
In this database, Mihail Marin provides a complete Black repertoire which is based on the so-called Open Spanish. The basic position of this line arises after the moves 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.0-0 Nxe4 6.d4 b5 7.Bb3 d5 8.dxe5 Be6. In the introduction, GM Marin writes: "The Open (or Tarrasch) Variation in the Spanish Opening has fascinated me ever since the 1978 and 1981 Karpov-Kortschnoj matches, during which the challenger regularly used it, coming up with many new ideas. Before that, the system did not enjoy a good reputation, but the intense rehearsal during the matches provoked a real boom of the opening. For many years I had an intense but purely "platonic" sympathy for it. I finally decided to include it in my repertoire when I understood that playing the Sicilian against players like John Nunn was pure suicide. And as a reward, my first game with the Open Spanish ended in a draw against the same Dr Nunn, who one year earlier had made me the unwilling co-author of a brilliancy prize in the Najdorf! The aforementioned matches also induced a new fashion trend from White's point of view, but during the '80s, Kortschnoj introduced many new ideas in tournament games. Around 1990 a serious crisis happened, after a crucial loss of Kortschnoj to Hjartarson. I managed to play it for a few more years, switching systems when I feared concrete opponents' preparation, but around 1994 I had to resign to the evidence: Many of my favourite lines did not look playable anymore. Revisiting the variation after such a long time was refreshing. When writing this database I understood that at this stage of theory there are certain systems (mainly 9.Nbd2) in which Black has to go for dynamic play (and not for static positions, as I used to do)."