DALLAS — With extreme heat forecast for the 2018 AT&T Byron Nelson Classic, hometown hero Jordan Spieth was asked what he does to prepare and maintain focus. “Layoff the sauce every night, no alcohol,” Spieth said. “It makes a difference if you have two beers on a Tuesday, it really does.” Also, no red meat for this Texas Longhorn. “Stay away from big steaks. These are the kind of stuff you start to learn once you kind of feel sluggish,” he said. “I’m 24 and still kind of feel a difference here and there.”* Thursday’s forecasted high is 94 degrees, with 97, 96 and 93 predicted for the other tournament days. Spieth is bullish on his prospects as he begins back-to-back hometown events. “I feel