2: Conceptual Framework
Part 3: High-Level Results
5: Empirical Data for AL 2000
6: Example: David Wells in AL 2000
7: Yearly Results for 1978-2001
8: Top Stars
Part 9: Concluding Remarks
In this article I have presented a new stat called Win Values that I developed
to evaluate the contribution a starting pitcher makes to his team over the
course of a season.? Win values are calculated on a game-by-game basis and
take into account not only the number of runs the pitcher allows but also
the number of runs his own team scores.? Only by considering the context given
by the game?s score can we properly evaluate the contribution each starting
pitcher made in the game relative to the contribution the team could have
expected from a league average pitcher.
We have seen that win values identify the
very best seasons of the past 25 years, such as Dwight Gooden?s 1985, Greg
Maddux in 1995, Roger Clemens in 1990 and 1997, Pedro Martinez in 1997, 1999,
and 2000, and Ron Guidry in 1978.? In addition, we have seen how win values
integrate run prevention information with W-L information to give an accurate
evaluation of a pitcher?s contribution to his team winning.
By looking at the league leaders in win values
from 1978-2001, we identified several instances in which the Cy Young award
was given to a pitcher who contributed much less than other pitchers in the
In the final section, I presented the seasonal
win value totals for 23 top starting pitchers in the 1978-2001 period.? We
saw that there were a few pitchers for whom their career win value total is
significantly different than their WAA figure.? Ron Guidry, Orel Hershiser,
Jack Morris, Dwight Gooden, Bob Welch, and Dave Stewart all contributed more
to their teams than is reflected in their ERA?s.? Dave Stieb, on the other
hand, seems to have contributed significantly less to his teams than is reflected
in his ERA.
Traditional sabermetric stats such as Wins
Above Average are designed to give a fairly good estimate of how much each
pitcher contributed, looking backwards, and to be good predictors of what
the pitcher is likely to do in the future.? In contrast, win values were designed
solely to be the best estimate of what the pitcher actually contributed to
his team?s actual winning of ballgames.? It is a descriptive stat, meaning
that it looks backwards at what happened and attempts to ascribe credit (or
blame) to the starting pitcher of each game.?
Since win values takes into account a pitcher?s
run support, it is apt to be an inferior predictor of a pitcher?s future performance.?
This is a downside that I am willing to live with in light of the improved
accuracy of our evaluation looking backwards.? When I look in a Baseball Encyclopedia
and see that Sandy Koufax is deemed to have contributed 6.0 wins to the 1966
Dodgers, I want that figure to be the best possible estimate.? I believe Win
Values is the best possible estimate that I have seen.
I encourage readers to provide feedback on the Win Values system to my email
address listed below.? Finally, I would be happy to send the file containing
the seasonal win values for every pitcher from 1978-2001 to anyone who is
Rob Wood is a management consultant living in Mountain View, California.?
Feedback on the article is encouraged.? He can be reached at firstname.lastname@example.org
Posted: August 19, 2002 at 05:00 AM | 0 comment(s)
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