What's the main purpose for a Police Officer to use his Baton?

I prefer the TASER over my baton but carry one anyway. The baton can take out a car window if you have to extract a accident victim, the TASER can drop someone from 25 feet away. A baton can be used for leverage to pry someones arm behind the back. A Taser can keep a person incapacitated until backup arrives. And, if someone is trying to stab me I'm going to shoot them with my pistol, not the TASER and I'm sure not going to let them close enough for the baton.