Based on wars of the past- failed to acknowledge Russian and French improvements and learning from mistakes of previous wars. Based on assumptions- they assumed the French war effort would be disorganised and that Russias poor infrastructure and disorganisation would cause an 8 week delay which was an incredibly risky prediction that didn’t pay off. It was inflexible, had no alternatives and relied on speed when they had railway issues. Also casualties couldn’t be replaced as they had a smaller army