Citations:give someone his head

Etymology citations

 * 19th century, in Transactions of the Rhode Island Society for the Encouragement of Domestic Industry in the year 1858 (1859, Providence, Knowles Anthony & Company, page 151):
 * "When horses stumble, they often break the bearing-rein, and thus getting the head free, are enabled to save themselves. We all know, that when a horse is down, the first thing done is to give him his head, that he may get up... the surest way to keep a horse on his legs, is at all times to give him the free use of his head."
 * 20th century, in "HORSE RACING; Perfect Run for Zito Except for the Finish", New York Times, May 22, 1994:
 * "'That's exactly where I wanted the horse,' Zito said. 'Everything was perfect. That's the way the horse wants to run, so you've got to give him his head.'"
 * 21st century, in ESPN Horse Racing, "Baffert horses finish 1-2 in San Rafael", March 1 2003:
 * "He kind of didn't know what the first turn was about, and I had to give him his head to make the turn..."