A Good Dog Makes It Easier...

[ed]

Yes

[alex]

Absolutely!

But bad trainers can screw up a good dog (very unlikely) and some good once can make a nice sport dog from not so great puppy (very possible)!
A lot also depends on the foundation training and many more other things

About this guy's comments:
Obedience was also very difficult. My dog was very distracted and lazy.
Wow and very sad - to me it is not acceptable!
It tells me nothing about the dog but does tell me a lot about the trainer

I believe that good trainer can make a good obedience with not such a great dog (I'm talking about schutzhund) but almost impossible to make that dog be good in protection...