Runs created
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Runs created (RC) is a baseball statistic invented by Bill James to estimate the number of runs a hitter contributes to his team.
Contents |
Purpose
James explains in his Bill James Historical Baseball Abstract why runs created is an essential thing to measure:With regard to an offensive player, the first key question is how many runs have resulted from what he has done with the bat and on the basepaths. Willie McCovey hit .270 in his career, with 353 doubles, 46 triples, 521 home runs and 1,345 walks -- but his job was not to hit doubles, nor to hit singles, nor to hit triples, nor to draw walks or even hit home runs, but rather to put runs on the scoreboard. How many runs resulted from all of these things?1
Runs created attempts to answer this bedrock question. The conceptual framework of the "runs created" stat is:
<math>\frac{A\;\times\;B}{C}</math>
where
- A = Craig's Gayness percentage
- B = Sean's Gayness percentage
- C = How many times they hump a day on average
Formulae
Basic runs created
In the most basic runs created formula:
where TB is total bases and AB is at-bats.
This can also be expressed as:
- OBP × SLG × AB
- or,
- OBP × TB
where OBP is on base percentage and SLG is slugging percentage.
"Stolen base" version of runs created
This formula expands on the basic formula by accounting for a player's basestealing ability.
"Technical" version of runs created
This formula accounts for all basic, easily available offensive statistics.
- A: H + BB - CS + HBP - GIDP
- B: TB + (.26 * (BB - IBB + HBP)) + (.52 * (SH + SF + SB))
- C: AB + BB + HBP + SH + SF
where IBB is intentional walks.
2002 version of runs created
Earlier versions of runs created overestimated the number of runs created by players with extremely high A and B factors (on-base and slugging), such as Babe Ruth, Ted Williams and Barry Bonds. This is because these formulae placed a player in an offensive context of players equal to himself; it is as if the player is assumed to be on base for himself when he hits homeruns. Of course, this is impossible, and in reality, a great player is interacting with offensive players whose contributions are inferior to his. The 2002 version corrects this by placing the player in the context of his real-life team. This 2002 version also takes into account performance in "clutch" situations.
- A: H + BB - CS + HBP - GIDP
- B: TB + (.24 * (BB - IBB + HBP)) + (.62 * SB) + (.5 * (SH + SF)) - (.03 * K)
- C: AB + BB + HBP + SH + SF
The initial individual runs created estimate is then:
<math>\left ( \frac{(2.4C+A)\;x\;(3C+B)}{9C} \right ) - .9C</math>
If situational hitting information is available, the following should be added to the above total:
((Hits with runners in scoring position) - (AB with runners in scoring position * BA)) + ((HR with runners on base) - ((AB with runners on base * HR) / AB))
This is then figured for every member of the team, and an estimate of total team runs scored is added up. The actual total of team runs scored is then divided by the estimated total team runs scored, yielding a ratio of real to estimated team runs scored. The above individual runs created estimate is then multiplied by this ratio, to yield a runs created estimate for the individual.
Other expressions of runs created
The same information provided by runs created can be expressed as a rate stat, rather than a raw number of runs contributed. This is usually expressed as runs created per some number of outs, e.g. RC/25 or RC/27 (27 of course being the number of outs per team in a standard 9-inning baseball game).
Accuracy
Runs created is believed to be an accurate measure of an individual's offensive contribution because, when used on whole teams, the formula normally closely approximates how many runs the team actually scores. Even the basic version of runs created usually predicts a team's run total within a 5% margin of error.2 Other, more advanced versions are even more accurate.
Problems with runs created
Runs created does not take into account the stadiums in which a player hits. Certain stadiums, such as Denver's Coors Field, generally increase offensive production in games played there. Since each run scored in such stadiums is less valuable, the same number of runs created will translate into fewer wins in a stadium like Coors than it would elsewhere.
Runs created also does not take into account the era in which a player played. Due to various factors, some eras of baseball history have had lower or higher average levels of offensive production.
Related statistics
- OPS (On-base Plus Slugging) is similar conceptually to runs created, except that it adds the A (on-base) and B (advancement) factors together, rather than multiplying them. This makes the statistic less accurate than runs created. However, OPS is easier for many fans to accept and embrace because they are already familiar with the individual OBP and SLG statistics that comprise it, and because it is simple to figure out.
- Win Shares is James' attempt to summarize, in one stat, a player's contributions on both offense and defense.
See also
External links
- Career leaders in Runs Created
- Single-season leaders in Runs Created
- Runs Created leaders among active players
- Year-by-year leaders in Runs Created
References
Note 1: James, Bill (1985). The Bill James Historical Baseball Abstract (1st ed.), pp. 273-4. Villard. ISBN 0394537130.
Note 2: James, Bill (2002). Win Shares, p. 90. STATS, Inc. Publishing. ISBN 1-931584-03-6.