showdown or grinding home run derby?
Which gets you more xp?
You'd need to track how much each can earn you per hour to make that decision. For me it would be HR derby because I stink at Showdown.
But in the end, if it ain't fun for me then I am not playing a mode for the sole purpose of grinding XP
Derby earns you more per hour, and you have no chance of "failing" but it's a boring, monotonous grind.
Showdown earns you a little less, is more engaging and fun to play, but if you fail you end up with A LOT less xp.
If you're solely grinding for xp I suggest mixing it up. But hey, do whatever you want.