HI, I have a question about the theocs.I have noticed when building c/s' I have to build 30 to gain 10 bpt and that is only a 25% speed increase not 40% at 40% I should only have to build 24 c/s' to gain 10 bpt ???

30 CS normally gives 7.5 bpt, and 7.5*1.4 = 10.5

Every 60 CS you build will give you 21 more bpt, exactly like it should. The next 30 CS you build will give you another 11 bpt.

Its a 40% building speed increase, not a 40% decrease in the number of construction sites needed. If it was a 100% build speed increase, that obviously would not mean a 100% decrease in the number of construction sites needed. You are confusing how the bpt bonus is calculated. 40% building speed increase means you take your normal bpt and multiply it by 1.4, rather than taking the number of construction sites you need for a certain bpt and multiplying it by 0.6

Rockman's explanation is correct.

thanks I will take note of that when I am figuring turns :)

BPT = (CS/4 + 5) * 1.4 :)

http://wiki.earthempires.com/index.php/Formulae

or, what I find more useful when you set a BPT goal:

CS = (BPT/1.4 - 5)*4