LOUISVILLE, Ky. - The expected full field for Saturday’s Kentucky Derby will create a scenario none of the 20 who go into battle have ever seen before, or will again. Young nerves will be tested in such a large field by the jostling for position, tight spaces, and fierce challenges.  The experience is impossible to replicate or fully prepare for, although most youngsters get traffic training in company as part of their basic education. John Ortiz, who will send out his first Derby starter in Barber Road, explained the process of instilling competitiveness and confidence.  “I put them in company of threes or fours,” Ortiz said. “I like to bunch them up, teach them to split, to go up the rail. Even in breezes, we put them real close. And some horses really like it - they take to it and develop the skill.” Once he caught on, Barber Road thrived on the competition.  “At the beginning, obviously, they’ve all got to learn it, because they’re herd animals,” Ortiz said. “But once he figured it out, he enjoyed it. He’ll sit there covered up, and as soon as he sees a little daylight, he’ll jump in the hole now on his own.”  Barber Road’s early training has served him well in large fields in the Oaklawn prep series this year. He was second in a field of 13 in the Smarty Jones and a field of 12 in the Southwest; split foes to be third in the Rebel’s field of 11; and came up the rail late to be second among nine in the Arkansas Derby.  “Just watching him come down the stretch, I know he’s going to barrel his way through,” Ortiz said. “When he’s spotted a hole, he’ll go through it. He is a gutsy horse.”