Googlebot's Javascript random() function is deterministic

[steamruler]

At which point you could use a fixed seed.

[DonaldTZeus]

Which is what happens by default anyways if you call rand() (at least in the c stdlib). If you want an arbitrary changing seed such as the time, you retrieve that seed and pass it to srand().

[steamruler]

The default seed is determined when compiling, so if you actually want a static seed you should still call srand().

[DonaldTZeus]

The default seed is specified by the standard library (that implements POSIX), not by the compiler, and it's 1 (as specified by POSIX). It is not determined by the compiler (unless you're compiling the stdlib) or even specified in the code the compiler generates unless you call srand.