Peter over at Mariner Musings goes through the M's and Expos' lineups to see if one good team could be made from both their lineups. If you're curious, go see what the answer is. Buried in that post is this little example of why batting average is so over-rated as a statistic, something I know in my head but have a hard time accepting intuitively. But when Peter compares left-fielders, he gets:
Raul Ibanez (.268/.330/.505, 23 XBH, 16 BB, 194 AB)
Brad Wilkerson (.236/.355/.455, 21 XBH, 36 BB, 191 AB)
Those averages are Batting, On-Base Percentage, and Slugging. XBH is extra-base hits. If someone offered you a .268 hitter or a .236 hitter which would you take? But Peter rightly notes that "essentially, the difference between Wilkerson and Ibanez is 5 singles (in Ibanez’s favor) and 16 walks (in Wilkerson’s favor). That’s 11 more times on-base, a.k.a. “11 fewer outs”, in Wilkerson’s favor." It's not like Wilkerson's advantage in OBP and Ibanez's in batting average cancel each other out: Wilkerson has been the better batter this year.
Oh, and by the way, Wilkerson is getting paid a near-league-minimum $375K this year, far less than Raul's near-$4M salary.
To be fair, Ibanez's isn't a totally "empty" batting average (see Dan Wilson for that). But I think the comparison here between Ibanez and Wilkerson is instructive.