It was about time. After 19 seasons and a record 985 appearances, 46-year-old knuckleball Pitcher Hoyt Wilhelm packed his bags in California last week and headed home to Georgia. After all, Wilhelm is a year over the beginning pension age under the players' new retirement plan and he deserves to spend his declining years with his family. The trouble from the opposition's standpoint—is that Wilhelm does not seem to understand about retirements or declines. Traded to the Braves in a waiver deal with the Angels, he arrived in Atlanta just in time to relieve the Braves' only other reliable reliever, Cecil Upshaw, who was dead tired after 55 appearances this season. Wilhelm quickly scored a pair of saves in his first two games with his new team and put Atlanta back into first place in the National League's tight Western Division. The addition of Wilhelm not only makes the Braves a tougher team to beat down the stretch, but it also gives the team the best one-two knuckleball combination in baseball. Atlanta's No. 1 knuckleballer, of course, is Phil Niekro, who won his 20th game last week. This is heady stuff for almost everybody in Atlanta except 20-year-old rookie Catcher Bob Didier. Didier has had remarkable success lunging for Niekro's knuckler this season, but Wilhelm is a whole new problem for him. "Catching Hoyt may be tougher," he says. "I've detected a pattern with Phil's knuckleball. It usually breaks down. But Hoyt's jumps a lot of different ways." Wilhelm, who throws his floater almost effortlessly, claims he will not retire for another year or two. By then, unless he has discovered a pattern in Wilhelm's tosses, too, Didier may be thinking of his own retirement.