Sabermetrics 101
Why batting average lies to you, and what to look at instead.
For over a century, baseball evaluated hitters on two main criteria: Batting Average and Runs Batted In (RBI). Sabermetrics fundamentally dismantled this approach.
The Flaw of Batting Average
Batting average (H / AB) treats all hits equally. A single is worth the same as a home run. Furthermore, it completely ignores walks (BB) and hit-by-pitches (HBP), treating them as non-events rather than positive outcomes that avoid outs.
Key Concept: OBP (On-Base Percentage)
(Hits + Walks + Hit by Pitch) / (At Bats + Walks + Hit by Pitch + Sacrifice Flies)
The Flaw of RBI
Runs Batted In is heavily dependent on context. A player hitting behind three high-OBP guys will inherently have more RBI opportunities than a player hitting behind three guys who strike out constantly.
Enter wOBA
Weighted On-Base Average assigns linear weights to every offensive event based on its run expectancy impact. A double isn't just "better" than a single; it's exactly 1.25x more valuable in terms of expected runs.