Yes street fights are different than sparring but to take away the application and principals and discard them because they are developed in a controled environment is very closed minded. 90% of the world population does not even know how to generate power when attacking. Even if you have a basic understanding of leverage and principals of power, you have an advantage...the main focus one must have is to attack relentlessly....There is a kid in our class that does this..he has rage fueling his perpetual motion on his attacks...granted his technique is terrible, but it is good to spar him, because in real wold environments you will not be able to judge the actions of your attacker by the movement of their bodies. Oh and another thing...use your knees and elbows during the street and not just the feet and fists and attack the vital parts of the human body...make it your single goal to attack that person at that location and you will succeed. You have to destroy your opponent in the street and bring max punishment, because he plans to do the same to you. Because of sparring I was able to apply empty mind and intimidate and detour a potential attacker. The confidence that you receive from sparring is part of the key to unlock your truth in warrior potential. Plus physically...it helps your footwork, timing , reaction and accuracy of application applied.