1) Lilly is a bottom of the rotation pitcher, so his team will be facing other bottom of the rotation pitchers, meaning they will score a lot of runs against pitchers like Colby Lewis, Ryan Franklin, and John Lackey , thus making it easier for him to get wins. Rueter is a top of the rotation pitcher, meaning his team (though they have a nice lineup) will be facing pitchers like Schilling, Eaton, Nomo etc. when Rueter pitches, making it harder for him to get wins.
2) Lilly 2.48K/BB (77/31), 6.93K/9
Rueter 1.41K/BB (76/54), 2.36K/9