Just watched the Aesoft. I can see why that is a painful loss. Sure there were some mistakes like switching out Politoed when you already controlled the weather--but some of this is just practice. I highly recommend that you save your logs if you don't already so you can analyze your losses. After each loss, note one or two pokemon that caused you trouble in a spreadsheet. For this case, Dragonite and Volcarona were issues. Once you get a series of losses and a repeated pokemon shows up, that is a good sign to make a change. The only way to get to 1050 from 900 is to practice by battling. Team building is part of the equation--the most important part--but knowing how to respond to threats improves your teambuilding skills, as well. Don't be afraid to have a few bad battles. We all started as n00bs here, even the best of us. Good luck and keep practicing :)