This position resulted from a Sicilian Dragon. Something went a bit wrong for white. But he didn’t notice it and played 12. Be3?
Why is this a mistake?
Your intuition probably told you: sack the exchange! That is exactly what Simagin did. Mind you this was in 1947. In that time this kind of exchange sacrifices were not common knowledge. Nowadays, every Sicilian player has a nose for this kind of moves. View the complete game…
Source: ‘Mastering Positional Sacrifices’ by Merijn van Delft (New In Chess)
Michel's Chess Blog 