Joe Nathan retired Friday with 377 career saves, including 260 with the Twins, the greatest relief pitcher in team history. Though he never started a game, and thus pitched just a fraction of the innings of a starter, he still ranks among top 10 Twins pitchers in Wins Above Replacement, which measures overall individual contribution:

49.3 Bert Blyleven

45.5 Brad Radke

35.4 Johan Santana

31.9 Jim Kaat

27.2 Frank Viola

26.1 Jim Perry

24.7 Dave Goltz

19.1 Kevin Tapani

18.4 Camilo Pascual

18.3 Joe Nathan

Nathan’s ninth-inning value shows up in Win Probability Added, which quantifies how much each batter faced adds to the probability of his team winning. He’s the Twins’ all-time leader among all pitchers (Johan Santana is second), and ranks fourth among relievers in major league history:

56.5 Mariano Rivera

34.1 Trevor Hoffman

32.1 Rich Gossage

30.6 Joe Nathan

28.8 Billy Wagner