It is interesting to note that Babe Ruth and Walter Johnson are 1-2 on the all-time wins-above-replacement list. Ruth had a career WAR of 182.6 and Johnson of 167.8. Cy Young and Barry Bonds are 3-4.
The first three accumulated those stats in 154-game seasons rather than the current 162-game season. Eight additional games over a 20+ year career is an additional season to accumulate stats with most of those additional games occurring during their prime.
I think Bonds stats should have an asterisk next to them as his success may be attributed to performance enhancing drugs. Ruth relied on hot dogs and beer.