2) Kenley Jansen
Kenley Jansen‘s major league career conveniently spans the entire past decade. Signed as an undrafted free agent catcher in 2004, he has developed into one of the elite closers in baseball. In 2019, he recorded his 300th save. Only Craig Kimbrel (346) ended the decade with more saves than Jansen (301).
While Jansen has regressed over the past few seasons, from 2012-2017 he was one of the most dominant relievers in the majors. Over those six seasons, his ERA finished below two runs three times, and never higher than 2.76. Overall, he finished that impressive stretch with a 2.07 ERA in nearly 400 innings of work (396.1), striking out 604 batters, while walking only 85 in that time. That equates to an insane seven strikeouts per walk ratio (7.11).
Closers are judged by their performance in the biggest games. Jansen has had so many opportunities in the postseason, he is bound to have a few bad ones mixed in with the good, but over 41 playoff appearances, his ERA is 2.01, having allowed just 11 earned runs in 49.1 innings of work.
Few players crossover from the disappointing final years under owner Frank McCourt to the success of new ownership like Jansen does. He was the last man on the mound for countless Dodger wins in a decade they won an awful lot of games. He is the second best pitcher of the past decade.