LONDON – Bob Baffert sometimes called Arrogate “The Blue Locomotive,” a steel gray colt with a relentless stride who, once he gained momentum, was nearly impossible to stop. The Arrogate train went off the tracks midway through 2017, but a quiet end to Arrogate’s journey doesn’t erase the memorable stops along the way, and Arrogate’s superiority was rewarded again Tuesday when he was named the Longines World’s Best Racehorse for 2017 by the International Federation of Horseracing Authorities at an awards luncheon at Claridge’s Hotel.