Lion Air pilots struggled against Boeing’s 737 MAX flight-control system, black box data shows
[emphasis mine]
...The data shows that after this cycle repeated 21 times, the captain ceded control to the first officer and MCAS then pushed the nose down twice more, this time without a pilot response.
After a few more cycles of this struggle, with the horizontal tail now close to the limit of its movement, the captain resumed control and pulled back on the control column with high force.
It was too late. The plane dived into the sea at more than 500 miles per hour.