I honestly can't remember a single dropped chain in about a decade of TTing on 1×n (for n>1), although I'm pretty sure my dad dropped a chain at least once between 1969 and whenever he got a front dérailleur, i.e. about 2006. In the olden days, all the chainring teeth were full-sized, we didn't have reduced teeth at the shift points, but we did have bushingless chains from about the mid 70s (thanks SEDIS) and even shorter chainstays than modern bikes.
I honestly can't remember a single dropped chain in about a decade of TTing on 1×n (for n>1), although I'm pretty sure my dad dropped a chain at least once between 1969 and whenever he got a front dérailleur, i.e. about 2006. In the olden days, all the chainring teeth were full-sized, we didn't have reduced teeth at the shift points, but we did have bushingless chains from about the mid 70s (thanks SEDIS) and even shorter chainstays than modern bikes.