It’s hard enough for bettors to focus on a 50-1 shot like Mine That Bird. “Who’s that horse?” is a common refrain when a long shot enters the picture. But for a race caller who must keep track of 19 horses, the job is doubly difficult.

Tom Durkin, who called the Kentucky Derby for NBC, appeared to lose sight of Mine That Bird’s dramatic move around the far turn and in the homestretch of the Derby, when the winner slipped past Join in the Dance to seize control of the race.

Coming out of the far turn, Durkin sensed that the front-runners were tiring.

“Join in the Dance has a tenuous lead,” he said, then cited Regal Ransom, and, excitedly, Pioneerof the Nile as horses who were also on the lead.

At that time, Mine That Bird was charging on the inside. Durkin then called out Musket Man and Papa Clem, after Mine That Bird was in the lead. Durkin seemed to stammer for a moment about a horse on the inside.

By the time Mine That Bird received his second mention of the race — the first was after the first half-mile — he already had three lengths on the field.

Durkin, seen by many as the best American race caller, rarely makes a mistake. In 1993, he correctly identified Arcangues, a 133-1 long shot, as he charged to the front in the Breeders’ Cup Classic.