But these physical errors can be greatly reduced through practice. I know it's a lot more fun to play a couple of games rather than spend the time alone practicing by yourself. I'm sure Jacobs, Haber, Lewis, Chapman, Bike and all the other great players you read about feel the same way. It all depends on your goals as a handball player. It is up to you.
Consistency is gained by many hours of specific practice.
If you learn to execute well, you have a chance of being a really good player. The reason I say chance is because there are many players with excellent execution who never win an important match. Just try to pick the eventual winner of a match on the basis of their warm-up routines, forgetting everything else you know about the players. Eliminating physical mistakes is essential to success, but this alone will not produce a championship brand of handball. What defeats these fine physical players most often are mental mistakes.