Lefty/righty matchups are key. If you get the unhittable curves, let them go for a strikeout if you have less than two outs. I find at least the next pitch are two are always hittable fastballs.
I’m in gold now. I keep 5* players only, as I need the xp. Not enough resources to level everyone right now. Started to trade some 5s in now though, since I’ve got some specialty players. You’ll kick yourself a bit if they come up as bonus guys, but they’re usually low tier bonus guys