Hitters, unlike pitchers, are easier to predict. Once a
player puts up a great season he is almost sure to give you a decent year
for the rest of his career. Like pitchers, rating unproven or underrated
hitters requires you to consider factors that are within the hitters control.
RBI, runs, and to a lesser extent stolen bases and batting average, can
be inflated or de-flated based on factors beyond the hitter's control (ie
ballpark, strength of team, manager's style). A better indication
would be to use stats like OPS and K/BB ratio.
OPS - For those unfamiliar with OPS, it is a number which represents
On Base % + Slugging %. It is a number which accurately
takes into account a wide range of offensive stats. OPS measures
a hitter's ability to get on base by walks and hits and it also measures
the hitter's ability to drive the ball for homeruns or doubles. It
also takes into account plate discipline, a quality that is extremely important
in a young hitter. The higher the OPS, the better.
K/BB ratio - This statistic measures whether or not a hitter
has a good batting eye and is able to lay off a bad pitch. The lower
the ratio the better. K/BB ratio is important for hitters that don't
have as much power as the big sluggers. For example, in a leadoff
man, managers tend to lean in favor of someone who has good speed and can
take walks. Putting the ball in play is important (ie. not striking
out). Because of their speed, they are more likely to beat out the
soft grounder that slower players may not. Also, if a prolific base
stealer can get on base with a walk, he can surely turn it into a "double"
by stealing second, which makes him more valuable than the singles hitter
that is impatient at the plate and has no speed. Sluggers tend to
swing for the fences and therefore have high K/BB ratios. A sign
of a natural hitter or one who WILL have success in the future is a hitter
who strikes out infrequently but hits for power. Vladimir Guerrero
is a free swinger who swings at bad pitches all the time, but he hits the
ball with authority and rarely strikes out.
With hitters, there are more intangibles that you have to consider
than you would have to with pitchers. Many offensive talents are
passed over (Piazza and Guerrero, for example) just because of those intangibles
that are missed by scouts. OPS and K/BB ratio will give you another
way to gauge hitters but they are by no means perfect. The factors
that should be considered when deciding whether or not to choose a hitter
is whether he is patient at the plate, has a good work ethic, is able to
make adjustments, is consistent, and makes good contact with the ball when
he does hit it.