Botvinnik generally sought tense positions with chances for both sides; hence his results were often better with the Black pieces as he could avoid lines that were likely to produce draws. He had a strong grasp of long-term strategy, and was often willing to accept weaknesses that his opponent could not exploit in exchange for some advantage that he could exploit. He confessed that he was relatively weak in tactical calculation, yet many of his games feature sacrifices – often long-term positional sacrifices whose purpose was not to force an immediate win, but to improve his position and undermine his opponent's. Botvinnik was also capable of all-out sacrificial attacks when he thought the position justified it. Botvinnik saw himself as a "universal player" (all-rounder), in contrast to an all-out attacker like Mikhail Tal or a defender like Tigran Petrosian. Reuben Fine considered Botvinnik's collection of best games one of the three most beautiful up to the mid-1950s (the other two were Alexander Alekhine's and Akiba Rubinstein's).