In 2015 only 2 pitchers in all the major leagues won 20 games. With the number of starts, with the use of relief pitchers for the last 3 innings and low pitch count limits for starters etc. etc. and five man rotations, very tough to win 20 games compared with the past (never easy to begin with). For a rookie, not impossible, but tough. Not compared with 749 complete games, But less likely than ever before.