  Pulsars are good clocks in the universe. One fundamental question is that why
they are good clocks? This is related to the braking mechanism of pulsars.
Nowadays pulsar timing is done with unprecedented accuracy. More pulsars have
braking indices measured. The period derivative of intermittent pulsars and
magnetars can vary by a factor of several. However, during pulsar studies, the
magnetic dipole braking in vacuum is still often assumed. It is shown that the
fundamental assumption of magnetic dipole braking (vacuum condition) does not
exist and it is not consistent with the observations. The physical torque must
consider the presence of the pulsar magnetosphere. Among various efforts, the
wind braking model can explain many observations of pulsars and magnetars in a
unified way. It is also consistent with the up-to-date observations. It is time
for a paradigm shift in pulsar studies: from magnetic dipole braking to wind
braking. As one alternative to the magnetospheric model, the fallback disk
model is also discussed.
