I lost my first tournament, and first fight at that against a guy who had been doing jitsu for 2 and a half years... It was white level and i had been doing jitsu for 5 months at the time... MIND you, i like the fact that he could not tap me and only won by points... but obviously pissed me off a bit.
In regards to sandbagging, i truthfully dont get it. Even if my coach told me to compete at white level when im a blue i dont think i would. Im still competing at white because i AM a white, and the day i win my tenth match (im at 3 out of 4 so far) ill only compete at blue and It will be that much more motivating to train because winning at blue feels much better than winning at white, same with purple over blue etc.
Jitsu is a journey of my own development and my own challenges. fuck sandbagging. ill welcome a third place in blue over an unfair gold in white any day.