OPS is just slugging percentage plus on base percentage. It's kind of a pretty useful stat and not exactly difficult to understand. WHIP Is walks and hits per innings pitched. Again, a simple and useful stat. I don't know about wins above replacement. I guess it's a pretty pertinent stat but I didn't really need a stat to tell me that a team is better off with mike trout than basically any other center fielder in the world
OPS seems kind of redundant
On base percentage is batting average plus walks
Slugging is batting average adjusted for extra base hits. So if you get a single it counts towards your batting average AND your slugging percentage
Why not just add walks and stolen bases to the calculation of your slugging percentage?