I interpret Ted Williams' famous "slightly upward stroke as the optimal way to swing" as hitting gold. But I believe there's a little nuance before that stroke happens. Getting in the zone too early pigeonholes the stroke to the angle that was committed to and requires elite pitch recognition. Think Juan Soto. He's in the zone early and late and leads the league in walks often. Elite pitch recognition and plate discipline. Another way to hit, and how I interpret Ted's quote, is to delay barrel application to further out front of the body. Then apply the barrel however you please, based on the pitch and approach. (In the image below, notice the arms are out in front of the body.) Being in the zone as long as possible is the method for the most room for error. But for the feel people (swing down), they believe that if the barrel stays close to the body and above the hands until out front, the arms can get extended and the barrel can work further and longer out front with adjustable direction. It allows one to let the ball travel while delaying the decision to apply the barrel, giving you adjustability and, hopefully, more game-time power. Pitchers are literally creating pitches in a lab to attack hitters with long swings. Late movement. More deception. Set-up pitches that mimic the early trajectory of their breaking pitches and offspeed. In-zone early swings (without elite pitch recognition) leave the hitter as one that can hit mistakes, which absolutely has a place in baseball, but when a pitcher is locating or not giving in, the swing down crew has a chance to come through with a knock. There's a million ways to hit, and doing it against pitchers that also practice (or get paid) requires one to make adjustments, however possible, to succeed and put the team in a position to win. Bruce Lee (iconic martial artist and creator of Jeet Kune Do) famously stated that he didn't like "styles" because they were a crystallization. A style is an unbending way of thinking that fails to bend in the heat of battle. What does a boxer do in a street fight when his opponent uses only kicks? In competition we must be living, breathing opponents that make it difficult to attack. Swing on deck. Hit in the game.