Each manufacturer seems to have a different way to measure fielding gloves. Ideally, take a glove on your hand, palm facing you. Take a tape measure and run it down the inside of the glove, with the tape touching leather all the way. Take the measurement from the top of the pocket to the bottom of the heel . In our experience, there is no major difference in performance.
Leather costs more but many players like the feel of a leather ball better.
Under wet conditions, synthetic balls may be the choice because they tend not to retain water as much as leather balls . Different types of hitters prefer different types of bat weights. A power hitter tends to favor end loaded bats while base hitters tend to like a balanced bat. However, every hitter has different preferences, so what applies to one player may not apply to another . Certain bats will offer no warranty.