Analysis has shown that when a given hitter puts the ball in play they get hits about the same percentage of the time no matter what the count (there are some small differences). With two strikes on them a hitter suddenly has the option of striking out and their batting average with two strikes drops drastically even though they get hits just about as often if they put the ball in play.
In addition players tend to hit the ball harder with less than two strikes.
Now we have to wonder if by continuously pitching around Bonds pitchers aren't "artificially" raising his batting average and his home runs per at bat because he so seldom has to worry about striking out.
Of course he'd hit more home runs and get more hits if they pitched to him but his home runs per at bat and batting average would almost certainly drop.
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