Career
Osnos competed in six Soviet championship finals from 1963 to 1968. In 1966 he finished in equal fourteenth place. In 1967, in the first Soviet championship to be run under the Swiss system, he finished in a 10-way tie for eighth place out of 126 competitors.
In his final Soviet championship in late 1968/early 1969, he finished in equal eleventh place.
In 1968, Osnos finished =1st in the Leningrad City Chess Championship, but lost the playoff against Valery Bykov and Alexander Cherepkov. Between 1968 and 1974 he was one of Viktor Korchnoi"s seconds, and in 1974 he was awarded the title of Honoured Trainer of the Russian SFSR. Osnos assisted Korchnoi during his narrowly lost World Championship Candidate"s final match against Anatoly Karpov in Moscow 1974.
Osnos co-authored with Peter Wells The Complete Richter-Rauzer, published by Batsford in 1998.