Mains: The RISP mystery

From SABR member Rob Mains at Baseball Prospectus on May 25, 2016:

In this article, I looked for evidence that some hitters perform better with runners in scoring position (RISP) than in other situations. (I didn’t find much.) To help me define perform, I calculated run expectancies with RISP and discovered that of common batting metrics (batting average, on-base percentage, slugging percentage, and OPS), slugging percentage correlates best to driving in runs. So I looked for hitters who slugged higher with RISP than in other plate appearances.

A couple commenters suggested that this is a low bar. After all, they reasoned, hitters should have a higher slugging percentage with RISP than without, for a number of reasons:

· Pitchers have to pitch from the stretch (though the perception that pitchers give up velocity by pitching from the stretch doesn’t appear to be true)

· Infielders must position themselves to hold runners on, opening up lanes for basehits that wouldn’t exist with the bases empty

· Similarly, with fewer than two outs and a runner on third, infielders may move up to prevent a run, creating additional opportunities for singles

· Batters face lesser pitchers, for the simple reason that good pitchers don’t allow as many batters to reach scoring position as poor pitchers. Last year the 25 pitchers who faced the most batters had a combined ERA of 3.26, FIP of 3.33, and DRA of 3.31 (weighted by innings pitched). The 25 pitchers who faced the most batters with RISP had a combined ERA of 3.88, FIP of 3.83, and DRA of 4.30

Read the full article here:

Originally published: May 25, 2016. Last Updated: May 25, 2016.