Casey Parsons vs. John Simmons — Career Comparison

Looking at the career totals, Casey Parsons and John Simmons are closely matched on the surface stats. Casey Parsons posted stronger numbers in OPS (.587 vs .513) and slugging (.321 vs .215). John Simmons had the advantage in on-base percentage (.298 vs .267). By the career numbers, Casey Parsons had the stronger overall case — though those totals don't account for the eras and run environments each player worked in.