The Monk keeps saying how the NL teams can't hit and how going from AL to NL for pitchers does them a world of good because the NL lineups have AT MOST seven good hitters (St. Louis and Houston, 2004) and usually max out at six; but AL lineups can have EIGHT or NINE good hitters (RedSax, Yanks, Rangers, Angels, O's). Now Tom Verducci provides the proof based on eight starters who switched AL --> NL from 2003 to 2004 and seven starters who switched from NL --> AL in the same period.
First, the cumulative numbers for the eight starters who started 20 games for AL teams in 2003 and switched to the NL:
2003 American 96-82 4.95 ERA, 1,450.2 IP, 2.2 BB/9, 5.8 K/9
2004 National 98-65 4.00 ERA, 1,455 IP, 2.6 BB/9, 6.1 K/9
Getting out of the AL was worth almost a full run in ERA (0.95). As expected, the pitchers struck out more batters but also walked more, perhaps owing to the additional intentional walks created by the pitcher's spot.
That's a 19.2% decrease in ERA! Each of the eight lowered his ERA.
Next, the NL starters who went to the AL:
2003 National 79-68 3.64 ERA, 1,269.1 IP, 2.9 BB/9, 7.6 K/9
2004 American 56-37 4.57 ERA, 793.2 IP, 2.8 BB/9, 6.5 K/9
. . . getting out of the NL added nearly a full run to their ERA (0.93), or almost exactly as much as the eight AL-to-NL jumpers saved in switching leagues. Again, they walked batters and struck out batters at slightly higher rates in the NL.
The 0.93 ERA jump is a 25.5% increase.
Number of NL pitchers to switch leagues in the DH era and immediately win the Cy Young Award = 0 (Pedro did it in year two). Number of AL pitchers to switch to the NL and win the CYA = 3 if you count Randy Johnson (2/3 of 1998 in Seattle, 1/3 in Houston, won 1999 CYA with Arizona; the others = 1984 Rick Sutcliffe, 2004 Roger Clemens).
That proof enough for you, Wongdoer?