5th Generation Russian AC

Sorry guys I know its getting boring talking about Russian stuff (specially because of the flames!) but i just thought this might be worth knowing about.

i also have some questions..

How do the Russians decide what to put in the AC when they dont have something to go against..

Sounds stupid and it probably is, but when i want to make something new, i look at what is already out and then tried to do something better, but with aircraft like the JSF, and the F/A-22 just entering service how do the Russians know what to go up against???