Brushless motor problem

So i want to control my brushless motor per esc. In der arduino code i wrote esc.writeMicroseconds(1050), and nothing happend, i wrote 1300 and nothing happend. But at 1580 the motor started to go full speed and almost hurt me... How can that be? I read that the value for neutral position is 1500...
When I tested the motor earlier this week, it went really slow at 1550 and gradually speed up with increasing value, which really lets me think...

Some ESCs are programmable, each kind is likely to have different response out of the box - remember
what they are designed for, joystick control, ie its expected a human is paying attention in a feedback
loop.

With high power ESCs expect two things - unexpected full power operation, and sudden bursting into flames,
and prepare accordingly - don't assume there are any real safety features built into hobby-level devices like this.