sure?

 

It looks to me that with use predictor off it assumes that the crank is moving at a constant angular velocity equal to the last period's velocity. With is on, it assumes that if it detects acceleration (that the velocity has changed in the last period vs the previous one), that it accelerates at a constant rate, and adjusts the predicted ignition point accordingly.

 

Thanks for the cliff's, i've read that a few times to try to understand.