To apply them for real you need to be more skilful than your opponent because people will try to naturally try to escape, typically by either using muscular resistance or trying to twist themselves out. Part of the art is first breaking your partner's balance, so that (s)he loses the ability to effectively resist, as well as adapting to whatever response they (s)he manages to muster.
But what happens if your opponent is simply much, much better than you? Check it out:
Although the attacker is allowed to start to apply locks, at no stage does he control the defender's balance (or center). Quite the reverse!