To Each player’s age 30 season, Kershaw’s numbers are significantly better.

They both became everyday starters at age 21 but it took Koufax longer to become dominant. He wasn’t elite until he was 26.

Kershaw had a sub 3 ERA every year from his rookie season until he was 31 and won the triple crown and his first Cy Young at 23.

That’s part of what makes him so great. There has always been talk about different pitchers like DeGrom or Matt Harvey overtaking him but the thing is those guys are hardly younger than him. Other great pitchers from his generation got started a lot later and haven’t been able to stay healthy or effective.

Only Verlander and Scherzer have been able to be consistently great like Kershaw.