The Soviet Championships were usually the strongest tournaments in the world during Vasiukov's main competitive period, surpassing the strength of Interzonals, with very few if any weaker opponents, since the arduous qualifying process eliminated the outsiders.
Since Vasiukov never placed near the top in Soviet Zonal competition, he was unable to earn an opportunity to play in an Interzonal tournament, where he might have done well in the mixed-strength fields featured there, as he excelled in similar circumstances in regular International tournaments.