This is the "statistician's rounding" as recommended in IEEE-754, so makes sense it is the default in R. https://en.wikipedia.org/wiki/Rounding#Round_half_to_e

This is the "statistician's rounding" as recommended in IEEE-754, so makes sense it is the default in R. https://en.wikipedia.org/wiki/Rounding#Round_half_to_even https://en.wikipedia.org/wiki/Rounding#Round_half_to_even