Superior development is a good advantage to have. However, as many chess players unhappily acknowledge, it is very transient. Many players have built up a significant lead in development only to see it fizzle away because they didn’t know how to take advantage of the opportunity. Of course, the importance of development is stressed very often. In fact, it is one of the 3 goals of the opening. Yet, so few players know how to utilize such an advantage!
Many players know that the opening of the position favors the two bishops. So, too, here the opening of the position favors the better developed side. If you have the superior development, your goal should be to open up the position. Usually this is performed via a pawn break. If you can post your pieces so as to support such a pawn break, and you have a lead in development, your pieces will control the whole board. Your rooks will have the time to occupy the open files, and your pieces will be coordinated. Meanwhile, while you are completely developed, control the center, and are ready to pursue play on the wings, your opponent hasn’t even completed his development! This rule has very little to no exceptions. Almost always obey this rule without question.
What should you do once you open up the position? Chess players often accumulate various advantages, but fail to follow through and capitalize them. You can’t let your advantage fizzle away. Given time, your opponent will complete his development. Given time, your opponent will be able to gain counterplay. Given time, your opponent will equalize. So don’t give your opponent time! Start capitalizing in on your advantages.
Often, this is realized through an attack. Once you have opened up the position, your pieces are coordinated, and you control the center (usually, central control comes with superior development in an open position, since your opponent’s pieces aren’t even putting up a fight!). So you start attacking. Think about it for a moment. You have castled, completed your development, and are attacking on one wing. Your opponent, on the other hand, doesn’t even have the pieces developed to come and defend! Chess is like a war in many respects, and it is here also. In a war, if your opponent’s troops are tied up somewhere else, you are free to deploy your troops into one area. You can then overwhelm his forces. The same holds true for chess. Your dynamic advantage of superior development can quickly be realized into an attack.