[botmeister]

I agree with what PMB is saying, use as little of the engine as you can. You should try and separate your code from the engine through a clean interface.

I don't know which functions will be better, but my guess is that rand() will be faster to call. The best reason to use your own random_long (etc) is that you can reuse the code for other projects.

For example, I built all my own timing functions and I don't use the engine for timing at all. Now I can use these same functions on other projects which is nice. My code is much cleaner too, and problems that some people had with the engine timing never affected me.