LOUISVILLE, Ky. – The horses for the 141st Kentucky Derby had left the paddock and were on their way to the track. Bob Baffert stayed behind and walked around, a bundle of nervous energy. The song “My Old Kentucky Home” came over the loudspeaker. “I hear this song, I think, ‘It’s almost over,’ ” Baffert said. “My job is done.” He was asked, after three Kentucky Derby victories and all he’s accomplished in the sport, if he still gets nervous for a big race. “Dude, I’ve been nervous,” Baffert, 62, said. “The day I don’t get nervous you better check my pulse. I’m dead.” Baffert had good reason to be nervous. His horses, American Pharoah and Dortmund, were the top two betting choices in the race. The minutes seemed interminable before the race. Baffert just wondered aloud, spewing random thoughts, trying to stay loose. “You just hope they run their race,” he said. “Somebody’s going to be happy. I hope it’s me.” He then turned to a few members of the press who were shadowing his every move and said, “I hope he’s as good as you guys wrote him up to be.” The horses were still on the track. Baffert was still a bundle of nerves. “I know how Mayweather and Pacquiao feel right now,” Baffert said. “Except they get paid.” If neither American Pharoah nor Dortmund were to win, “I get the big doughnut.” There were zero minutes to post. The horses were getting closer to the gate. Baffert turned his back to the big screen. “Can’t watch,” he said. Baffert said there are times when, if he can’t make it to the track for a race, he sits in his car, waiting for his cellphone to go off. “If this phone doesn’t go off,’’ he said, staring at it, he knows his horses didn’t run well. Jim Barnes, his top assistant, came to the paddock. He told Baffert that all was good. The horses both warmed up well. Baffert moved to the center of the paddock. His oldest sons Taylor, Canyon, and Forest were closest to him. His gave his wife, Jill, a good-luck kiss. Bernie Schiappa, a close friend and one of his owners, was close by. Baffert’s 10-year-old son, Bode, was behind Jill. The gates opened. Dortmund broke well and was on the lead under Martin Garcia. American Pharoah, under Victor Espinoza, broke alertly and was third, three wide entering the first turn. Baffert remained calm and said nothing. Around the middle of the far turn, it looked like Dortmund and Firing Line were getting away from American Pharoah. “Uh-oh, he’s in trouble,” Baffert said. Far from it. Dortmund, along the rail, and Firing Line, taken a few paths away from Dortmund by Gary Stevens, continued their tussle with American Pharoah, who was a few paths away from Firing Line. Inside the sixteenth pole, American Pharoah started to edge clear, and he would win the Derby by a length. Firing Line finished second, two lengths ahead of Dortmund, who suffered his first career loss in seven starts. A wild celebration ensued. Hugs from his three older sons got a little hairy when Baffert slipped and almost fell. Upset for a split second, Baffert then sought out his youngest son, Bode, who had never seen his father win a Kentucky Derby before. Baffert picked up his son and gave him a big hug and a kiss. “We did it,” he said. When the celebration calmed and he began the walk through the tunnel on the way to the winner’s circle, Baffert was able to compose himself. “I’m just relieved, very relieved,” Baffert said. “You know coming in here you got that kind of horse, and he showed it today. Pharoah probably didn’t run as well as he can, but he’s such a good horse. I’m just glad he got through here.” This was Baffert’s fourth Kentucky Derby victory, tying him for the second-most all time with his onetime rival but now good friend D. Wayne Lukas and H.J. “Dick” Thompson. That trio trails Ben Jones, who has six. But it was Baffert’s first Derby win since War Emblem won it in 2002. Since then, Baffert had participated in eight Derbies, with two second-place finishes. “This is different because I know I was coming in here with the best horse, and I was hoping you guys were right,” Baffert said. “I’ve been reading about him all week.” Jill Baffert broke down in tears. She wasn’t sure if her husband would ever win another Derby. “It’s huge,” she said. “I don’t even have words. I thought if we couldn’t win today, then it probably was just not going to happen. He was so excited about this horse, and both Pharoah and Dortmund ran awesome. I’m so glad we did it.” Last summer, Bob Baffert told his wife that American Pharoah was the best 2-year-old he had. He finished fifth, beaten 9 1/4 lengths, in his debut at Del Mar. Jill said, “If this is the best one we got, we’re in trouble.” “I might have jumped to conclusions,” she said. The American Pharoah story may be just beginning.