"Suppose you want to test the claim
"Pitching is 75% of baseball." If this were true, you would conclude
that the teams with the best pitching would be much more likely to win
the pennant than the teams with the best hitting. However, this isn't
the case. The league leaders in fewest runs allowed (which is both
pitching and fielding) win the pennant about half the time; the league
leaders in runs scored (which includes all of hitting) win just as
often. (Note the definition of offense here: if you measure hitting by
an incomplete measure such as batting average, you would conclude that
pitching is much more important.) Other unreasonable conclusions also
follow; for example, a team with 75% of its value in pitching would
never trade a regular pitcher for a regular hitter. Thus the claim must
be rejected. But if 75% is replaced by a number close to 40%, the
conclusions become reasonable. This is how a sabermetric argument
works."
From:
http://www.baseball1.com/bb-data/grabin ... festo.html