Defense ? If Rondo plays good D and Monta Ellis does'nt what is the reason? Mindset? Coaching? Ellis is faster?

Coaching System. Warriors Coach Don Nelson focuses on offense. He don't really focus on defense therefore makes Ellis not a good defender. Don't get me wrong, he can play D, just not that well. In the Celtics coaching system, Doc Rivers mainly focuses his team to play defense all the time. That is why Boston won the championship last year and the Warriors were close and didn't make the playoffs. Monta Ellis was faster than Rajon Rondo, but his ankle is still in healing process so right now I say Rondo is faster.