Jon Lester had a 5.50 earned average and a 1.53 WHIP in the month of May.
To put that in some perspective, only nine other pitchers in baseball (min. 20 innings) were worse this month. We're only talking about six starts, but that is hardly what you expect from the ace of the staff coming out of spring training.
Lester allowed 41 hits and walked 17 over 36 innings in May. Control is an issue. The big lefty averaged 2.8 walks per nine innings in 2008 and '09. He averaged 3.6 last season and 3.7 so far this season. His strikeouts have been fairly consistent, so it's not like his stuff isn't there.
The pitcher pop psychology term is "executing pitches." When asked what is wrong, Lester invariably says he's not executing.
There's also some stubbornness involved. Lester has fallen in love with his cutter, a very good pitch but one that opposing hitters are adjusting to.
In 2009, Lester's pitch mix was:
Fastball: 54 percent
Cutter: 20 percent
Curveball: 20 percent
Changeup: 6 percent
In 2011, it is:
Fastball: 47 percent
Cutter: 27 percent
Curveball: 14 percent
Changeup: 10 percent
Lester seems to be too intent on tricking hitters instead of attacking them. He also gets frustrated when umpires won't call certain pitches on the corner strikes. His stuff is too good to play that game. Overmatch the hitter and leave the umpire out of it.
At some point, Lester needs to get back to pitching off his fastball and using his cutter more as an out pitch. That's part of the reason he is being pushed back in the rotation until next Tuesday in New York.
The rotation as it stands now:
Tonight vs. Chicago: Alfredo Aceves
Wednesday vs. Chicago: Tim Wakefield
Friday vs. Oakland: Clay Buchholz
Saturday vs. Oakland: Josh Beckett
Sunday vs. Oakland: John Lackey
Tuesday at New York: Lester
Wednesday at New York: Wakefield
Thursday at New York: Buchholz
That gives Lester a week to think about what he is doing and how better to execute. The rest can't hurt either after he threw 127 pitches last night.