Baseball Analytics

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Rickey Henderson



Base Running Run is the sum of several baserunning components.  GAR (Ground Advancment Runs, SBR (Stolen Base Runs), AAR (Air Advancement Runs), HAR (Hit Advancement Runs, and Other Advancement Runs (OAR).  BRR represents the number of runs contributed by a player’s advancement on the bases above what would be expected based on the number and quality of the base running opportunities with which the player is presented, park adjusted, and based on a multi-year run expectancy table.  When you’re looking at the average run value in terms of a base/out state you subtract average run value from actual run value on a particular play where a base runner is involved.  The result, the difference, is the run value awarded to the base runner.  Confused yet?  Here’s a basic scenario to clarify.  We have a runner on 2nd and 1 out …

A ground ball to the right side would automatically advance the runner to third.  But what about a ground ball to third?  Let’s say our same runner advances to third and our runner going to first is thrown out 25% of the time, he stays at 2nd Base 70% of the time, gets thrown out at 3rd 2% of the time and beats the throw to third 3% of the time (batter reaches on fielder’s choice).  Let’s say the average base/out run expectancy (RE) of all of those, weighted by the frequency of occurrence is .25 runs.  If the runner advances and the batter is nailed at first, the runner gets credit for .25 runs (.5-.25).  If he stays at second base, and the average RE is of a runner on second base with 2 outs is .23 runs … then he gets docked for -.02 runs (.23-.25).  A runner gets docked or credited for the resultant run value of what he does minus the average weighted resultant run value of ALL base runners in that situation.  Multiple baserunners can get positive or negative credit on a particular play.

Below are samples of situations where a runner can obtain positive of negative credit:

  1. A hit, taking an extra base, not taking an extra base, getting thrown out trying to take an extra base (assuming there is no-one impeding his ability to advance).
  2. A batter gets thrown out trying to take an extra base on a hit (if he is successful, we simply credit it as a ‘double’ for it.)
  3. On a hit … the batter advancing, not advancing, getting thrown out while trying to advance when a runner is safe or out advancing an extra base.
  4. Tagging up on a fly out.
  5. Ground balls to the infield, runners stay out of a force or DP at 2nd base … whether or not the batter is out or safe on FC.
  6. Runner on second advancing on GB to SS/3B or not or getting thrown out advancing.
  7. Trail runner advancing, not advancing or getting thrown out when lead runner is safe or out trying to advance an extra base on a hit or an out (you can connect this scenario with #1)

Scenarios not considered …

A runner on 3B advancing, not advancing, or getting thrown out at home on a ground ball are not considered.  Runners advancing on WP or PB are also not considered.

All of the situations discussed are considered an opportunity for the base runner or batter.  The batter does enter the opportunity phase when he gets a hit unless the lead runner tries to advance an extra base and the batter has a chance to advance on the throw.

As we learned in the previous article, the value placed on base stealing players could be an inefficiency in the market, depending the success rate and frequency.  What about a great baserunner?  Could this be a piece of the pie that needs to be paid for before the rest of the baseball world catches on?  We entered the world of sabermetrics with teams paying for OBP … we correlated OBP with Runs and Runs with Wins.  Did we overlook the space between the notes.  Who are those base runners that add runs to their teams because of the ability to run the bases well?  Stay tuned to the next article- we’ll give you undervalued and overvalued players … and some prospects to keep an eye on.


Associate Scout- Sabrmetric Society (Science in Baseball Committee)- Former Head College Baseball Coach- Former Professional Player


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