OK, now do it for players who got 500 PA at age 20 then posted a .280 wOBA at age 23. If that's too specific, you can goose the parameters a bit. It's almost as if that's an outlier that may have little predictive power! But to cut through this terrible attempt to back into logic and get to the point, Castro is the very rare player who has the talent to produce from an incredibly young age, and therefore nonsense about "lots of players never improve after 22 because they aren't good enough!" doesn't apply, as the chart above indicates. That said, last season still happened, and it's not impossible that Castro is actually terrible or not good or whatever qualifier you want. That doesn't mean that that argument shouldn't face an incredible amount of skepticism since it flies in the face of thousands of MLB plate appearances from Castro, the standard of how players mature with age, and every comp of Castro's that we can find that has shown what he has shown. Believe whatever you want, I'll be the crazy one that thinks that Castro is still likely to improve after age 23. Is he going to improve on his age 23 season or improve on his age 21 season? He's a guy that gets value from making a lot of contact (been worse at this every season) and being able to pass at the league's toughest position (he's been passable at this one year out of four.) Like I said, there's enough good and bad history that either outcome is possible, but going "hey, look at ARod and Ken Griffey Jr at the same age" means about nothing to me. Castro is certainly not any of the guys on that list.