Good Statistics Versus Bad Statistics

This post is more of a reference or an index than a real, honest-to-gosh sabermetrics-analyzing post.

For those of you who aren’t sure what statistics to use when evaluating a player, look no further than this post.  Feel free to disagree, but I believe that these are categorized correctly.

Good stats are those that measure a player’s actual talent or skill level in a certain area.  Bad stats don’t account for luck or other such factors that get in the way of understanding a player’s true underlying skills and ability.

Good stats – use these to evaluate how good or bad a baseball player is:

• FIP (Fielding independent pitching)
• tRA (Park-adjusted, defense-adjusted, ERA-like stat)
• wOBA (Weighted on-base average)
• OBP (On-base percentage)
• SLG (slugging percentage)
• BA (batting average, and this one is debatable)
• UZR (ultimate zone rating)
• K/9 (strikeouts per nine innings)
• H/9 (hits allowed per nine innings)
• BB/9 (walks allowed per nine innings)
• BBs (walks accrued by either a pitcher or batter)
• Ks (strikeouts accrued by either a pitcher or batter)
• LD% (percentage of line drives hit by a batter of his total balls hit in play)
• GB% and FB% (percentage of ground balls or fly balls either hit by a batter or induced by a pitcher.  Remember, ground balls are better because they are more likely to turn into outs.)

Bad stats – don’t use these to evaluate players for their skills:

• ERA (Earned run average; you may as well look at total runs allowed if you’re going to go down this dark, dark path.  ERA is decent over a career sample, but not over anything smaller than that.)
• WHIP (So incredibly dumb that I won’t bother to explain it)
• VORP (which is pretty much WAR for cavemen)
• Defensive errors (this measures sure-handedness rather than defensive ability, and it certainly doesn’t measure range.)
• Saves (anyone can be a closer)
• Win-loss record (you should know better; anyone can win a baseball game if their team scores enough runs.  Even Carlos Silva.)
• RBI (runs batted in; this measures your team’s ability to get on base more than a player’s ability to hit with men on base)

So there you go.  Most of the good stats are available on www.Fangraphs.com and www.Statcorner.com.