Visitor Visa - B2

Hi, I am planning to apply for tourist VISA b1/b2. I am one of the 6 players of the Philippines that will participate in a gaming world championship. I just want to know my chances of passing a Visa. I don't want my money go to waste. The tournament that I'm attending is not sponsored. it's all my own expense. Ia m trying to picture my interview..I dont know if I can pass or not.. pls give me advice..I am 24 years old, male and single..employed. By the way if I win the tournament 20k US dollars will be the prize
I am only child and living with my mom so I dont have any intentions to work overseas. This tournament is solely my purpose. It's been a dream of mine.

so I am picturing my interview would went like this..

VO: Hello
ME: GOOD MORNING
VO: WHY ARE YOU GOING TO US
ME: I EARNED MY INVITE AND WILL REPRESENT THE PHILIPPINES IS GAMING WORLD CHAMPIONSHIP
VO: CAN I SEE YOUR INVITATION
ME: CAN SHOW
VO: HOW DID YOU GET INVITED
ME: I WON THE ASIAN CHAMPIONSHIPS AND EARNED MY WORLD INVITE
VO: WHERE IN THE US
ME: IN SF CALIFORNIA
VO: ARE YOU EMPLOYED
ME: YES, IM WORKING AS XX SINCE MARCH 2016
VO: WHO WILL PAY FOR YOUR TRIP
ME: MY MOM AND I WILL SHOULDER MY TRIP
VO: HOW LONG ARE YOU PLANNING TO STAY
ME: MAXIMUM OF 10 DAYS BECAUSE THAT'S ONLY THE NUMBER OF DAYS MY EMPLOER PERMIT ME
VO: OK YOUR VISA IS..............................WILL BE APPROVED OR DENIED?

IM SURE THE INTERVIEW WILL NOT GO THAT WAY..
CAN YOU GUYS SHARE POSSIBLE QUESTIONS THAT VO WILL ASK ME?
or possible interview flow?

pls help..this VISA application is stressing me out so bad