Well it all depends on what style you perfer to play, each type of goalie can be successful at breakaways you just need different skills. There are some goalies I've seen that sit almost inside the net, and still can stop their fair share of breakaways, while ive seen others rush out to almost the bottom of the circles. The key thing is making the shooter make the move and reacting, its alot easier for a shooter to correct himself after you force the hand than it is for you to react to a deke while you are lying on the ground. You also have to be agile enough to go post to post while keeping the 5-hole somewhat protected, I can't even count how many moves the shooter goes post to post. The last thing is a bit of luck, sometimes you'll do everything right and still will find the tiniest of holes and others not and of course there is the time you'll do nothing right and you'll throw a miracle leg pad at it and bat it away...