I know this might be an obvious question, but I've tried to find proper information for a while and not found anything definitive - the percentage bonuses - what is the stat or attribute that they're boosting?
If something gives an exit velocity boost of 20% then what does that mean?
It would be logical to be a 20% boost to the exit velocity, but that'd suggest an increase from, say, 100mph to 120 - or 110 to 132 - the most I've seen is about 119, so it doesn't seem to make sense...