Yes, and a key adaptation made by many is to start their swing a little earlier, which gives them less time to evaluate the pitch and more tendency to guess. A hitter could adapt by hitting to the opposite field more often, but few seem to choose that route. Casty's guessing and starting his swing quicker because of a slower swing is also reflected in his recent day/night splits, suggesting part eyesight, part bat swing as the problem.
Some hitters do continue to perform well into their mid-30s and even late forties. They tend to be exceptionally gifted athletes and hitters, which Harper is and Casty just isn't. They also seemed to be far more common during the PEDs era. Guys have had performance revivals at age 33 or a little later. In recent years, I admit that I have suspected illicit drug use in most cases.
To Zambonir:
It is easy to cherry pick the end of last season and assume that's the 'real Castellanos; Unless an eyesight or other physical problem was found or corrected, I find that argument unconvincing. He has 2.1 bWAR over 3 seasons and close to 1900 PA in Philly. I think that large sample size is the true measure of his current ability -- and being a year older in 2025 the expected range of his OPS performance should be flat to down. Fangraphs projection has him down very slightly.
No. It does not make sense to let him play through long slumps. It was forgivable last year, because thee team was able to win in the early season, despite negative WAR performance from him. This year's team doesn't look like a mid-90s win team, so losses incurred during a Casty slump could cost us a post-season appearance. As the roster looks today, I think Casty is only our 3rd best corner OF and Marsh is the best. Once he is healthy and hopefully gets his groove back at the plate, I think Rojas will again be our primary CF. I concede he may be well on his way to being the next Kingery-level washout.
