Odds of failure would perhaps be higher, given all the rest equal. Which is not - Soviet rocket engine school was at its golden age at the time, there were a lo

Odds of failure would perhaps be higher, given all the rest equal. Which is not - Soviet rocket engine school was at its golden age at the time, there were a lot of people both academically educated and who participated in large scale experiments with engines. Granted, today's capabilities allow us to surpass the level of sophistication achieved during the space race. However, we still need to try hard enough - and we know the support from governments is not as great. Limits of materials were pushed indeed. Some safety margins for materials were claimed as under 1.0 - i.e., 0.97 - that is, materials were pushed further than their limits. The idea was that since the engine is used once, we can use it in the manner that greatly reduces the life of the engine - and nobody would care, since a stage will be done with in a few short minutes. A lot of things were done quite unconventionally - remember SR-71, for example, or oxygen-rich pre-burners which were considered rather impossible. NK-33 remains unsurpassed even today by many criteria. Now it includes even the ability to work after 40 years of shelf line - which probably left the trace on engines reliability.