Being great for much longer than Pedro, or Koufax (another truly great pitcher with a shortened career) would indeed give someone a chance to make the Top 20. But Blyleven was only truly great in a few seasons ('73, '77, '84), never won a Cy Young, never even came in 2nd in the Cy Young voting (and granted, Cy Young voting, especially back then, was skewed towards W-L records)... looking at OPS+, Blyleven's best year of 156 is just 2 points above Pedro's career average.... If you look at Pedro's career stats, he scorches Blyleven in so many statistical categories (20-4 in 2002 with a 2.26 ERA in the Steroid era pitching in Fenway Park! I mean c'mon now! Or how about in 2000: 1.74 ERA, 0.737 WHIP, 11.8 K/9, those are truly dominant numbers that Blyleven never approached....) Pedro pitched in 476 games over the course of 18 years.... Koufax is another one who should be ranked much higher than Blyleven