Baseball Hacks

Measure Base Running Through EqBR

Measure base running proficiency through equivalent batter runs or extra base running percentage (XBRpct).

Twenty years ago, Bill James devised a set of formulas for measuring batting speed using readily available statistics. If you’re curious, here are the formulas:

SpS1: speed score based on SB percentage

SpS1 = ((SB + 3) / (SB + CS + 7) - 0.4) * 20

SpS2: speed score based on SB attempts

SpS2 = SQRT ((SB + CS) / ((H - 2B - 3B - HR) + BB + HP)) / 0.07

SpS3: speed score based on triples

SpS3 = 3B / (AB–HR - K) / 0.02 * 10

SpS4: speed score based on runs per time on base

SpS4 = (( R- HR) / (H + BB–HR - HP) - 0.1) / 0.04

SpS5: speed score based on GDPs

SpS5 = (0.055–GDP / (AB–HR - K)) / 0.005

Net speed score

Average of top four speed scores in the list

These measurements are useful, but they don’t take individual situations into account. For example, let’s consider SpS5. On average, a slow runner who follows a batter with a high on-base percentage will hit into fewer double plays than a similar runner who follows a batter with a high on-base percentage.

The Baseball America 2005 Prospect Handbook (Baseball America) has a great essay by James Click on a method for measuring base running. Aside from steals (successful and failed), good statistics aren’t available for measuring how well players run around the bases. In this hack, I explain quickly how to measure this statistic from the play-by-play data.

Equivalent Batter Runs

Click’s measurements are nice because they ...