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Baseball Analysis  Michael Hoban, Ph.D

Part 1 - Career Assessment
The Win Shares System
How to Judge a Career
The 1800/255 Benchmark - Jackie Robinson
The 2400/180 Benchmark - Pedro Martinez and Sandy Koufax
The 1500/150 Benchmark - Mariano Rivera

The Win Shares System

Michael Hoban, Ph.D.

The “Best Players”

Fans of any sport are usually interested in knowing who are (or were) the best players in the game.  At the end of the playing season, many fans enjoy looking back and being able to say that player A had a better season than player B.  And when a player’s career is ending, we like to conclude that “C was better than D and almost as good as E.”  Comparing athletes in this way is almost a national pastime in itself. 


Baseball fans are particularly fortunate in that no other sport rivals baseball for the sheer number of statistics available for comparing the players.  In fact, there are so many numbers available, that it often leads to confusion as to what to look at in order to judge how good a player really is (or was).  For many years, a player’s batting average (BA) was used to suggest who were the best hitters.  But, careful analysis over a number of years has now convinced us that a combination of on-base-percentage (OBP) and slugging average (SLG) is a better indicator of who were the most effective batters. 


Of course, in baseball, batting alone does not tell us who is a “better player.”  Fielding must also enter into the equation.  And judging fielding has always been more difficult than judging hitting.  The skills required of a good shortstop or catcher are much different than those required of a left fielder or a first baseman.  And attempting to judge who was the best “all-around” player has always been difficult.


But not to worry.  Over the years, there have been a number of dedicated people who have devoted a considerable amount of time into researching these questions.  Many of these analysts are members of an organization known as SABR (Society for American Baseball Research).  As a baseball fan and a mathematician, I have spent considerable time over the past fifteen years studying the various approaches that have been taken regarding the comparison of baseball players.  And I am happy to report that the most highly respected of all of these analysts, Bill James, has developed a system that I believe is a quantum leap ahead of all such systems in this regard.


Bill James is a dedicated researcher and a prolific and enjoyable writer.  For more than thirty years he has been considered the guru of baseball analysis.  In fact, in 2004, as a special advisor to the Boston Red Sox front office, he contributed to that team’s first World Series triumph in more than eighty years.


In 2002, Bill James published his book called WIN SHARES in which he introduced a new system that was the product of more than twenty-five years of research.  And it is this system that I am convinced is far better than any other that has been developed.  The method is so revolutionary that I believe that it is fair to say that FOR THE FIRST TIME EVER, we are able to validly look at and compare players (including hitting and fielding and pitching) no matter when they played or who they played for.  The key to the value of Win Shares is that it tells us how valuable a player was to his team each season.  And, of course, a player’s value to his team is what the game is all about.


Win Shares is a very complex system (the book is 728 pages long).  But it is not really necessary to understand every nuance of the system in order to appreciate its value.  The true genius of the approach seems to be two-fold.  First, like any valid evaluation system, it measures a player's value relative to the era in which he played and to the playing conditions under which he performed.  That is, adjustments are made to account for such things as playing in the “dead-ball era” or playing in a “pitcher’s ballpark.”  But the second (and more remarkable achievement) is that it appears to be able to measure a player's value regardless of whether he played on a winning or a losing team.  And it is not necessary to completely understand how the system works in order to enjoy the results that it produces.


Put as simply as possible, here is what the Win Shares system does - it tells us how good a season a player had.  It awards a team a certain number of win shares for the season – depending on the number of games that the team won during the season.  It then takes those win shares and distributes them among the players on the team depending on each player’s contribution to the team during the season.  And, as a rule of thumb, here is how the number of win shares in a season can be interpreted for an individual position player:


1.   30-40 win shares  =  MVP-type Season
20-30 win shares  =  All-Star Season
10-20 win shares  =  Solid Regular Player
4.    0-10 win shares   =  Bench Player


It is worth noting for example that the average MVP winner through 2004 had 33.4 win shares for the season. 


As an example of win shares results, here is the best season by some of the greatest players in baseball history:


Honus Wagner            1908                59 win shares

Babe Ruth                   1923                55

Walter Johnson           1913                54

Barry Bonds                2001                54

Mickey Mantle            1957                51

Ted Williams               1946                49

Ty Cobb                      1915                48

Stan Musial                 1948                46

Cy Young                   1892                44

Willie Mays                 1965                43

Hank Aaron                1963                41



Here is how the Win Shares system is described in The Bill James Handbook 2005 (ACTA Sports) – p. 361


“Bill James devised Win Shares to reduce a player’s statistics to a single number related to the number of wins he contributed to his team.  It includes offensive, pitching and defensive accomplishments.  The quality of the team does not affect an individual player’s Win Shares.  A great player on a bad team will rate as well as a great player on a good team. …

A Win Share is one-third of a team’s win, credited to an individual player.  The Win Shares credited to the players on a team always total up to exactly three times the team’s win total.  If the team wins 100 games, the players on the team will be credited with 300 Win Shares – 300 thirds of a win.  If the team wins 80 games, the players on the team will be credited with 240 Win Shares, always and without exception.


Win Shares are a great tool for evaluating trades, award voting and Hall of Fame credentials.”


I certainly agree with this last statement and that is why I feel that Win Shares (when used appropriately) can tell us which players definitely have Hall of Fame numbers.


To get a little more flavor of what Win Shares are all about, consider the following statements from Bill James himself in the Introduction to the book WIN SHARES (STATS, Inc., 2002).


“For many years, I have wanted to have a system to summarize each player’s value each season into a simple integer.  Willie Mays’ value in 1954 is 40, in 1955, 40, in 1956, 27, while Mickey Mantle in the same three years is 36,41,49.  If we had an analytical system in which we had confidence, and which delivered results in that simple a form, it would open the door to researching thousands of questions which are virtually inaccessible without such a method.  It would reduce enormously the time and effort required to research such questions, which can be accessed by other methods, but only with great difficulty.  (p.3)


We have dozens of methods to compare players.  We have piecemeal ways to put those together.  What we lack is a way of tying them all into a coherent analysis.  We need a comprehensive system, in which we have confidence, which has a place for all of the things we must think about when trying to assess value – productivity, park illusions, defense, playing time, contributions to winning teams.  Everything.  (p. 5)


This is the only analytical system I am aware of which is team-based, rather than derived from individual stats.  Most analysis builds up from the performance of individuals.  This analysis breaks down the performance of the team.  (p. 9)


This last point is crucial to understanding the uniqueness of the Win Shares approach and to appreciating the system.  Besides being comprehensive, it looks first at the team’s accomplishments and then determines each player’s contribution to the team’s success.



Win Shares – Comprehensive Yet Simple



As long as the game has been played, fans have attempted to compare players using the many statistics available to do so.  How many hits or home runs or runs-batted-in or runs scored or stolen bases did the player have?  What was his batting average or on-base percentage or slugging average or OPS?  And these numbers do not tell us anything about his fielding ability.


The true genius of Win Shares is that it includes ALL of a player’s contributions to his team and represents them in a single number.  So that if we want to know who had the best season, we can simply list those players who had the most win shares for that particular season.  As an example of the beauty and simplicity of the system, here are lists of the top ten players in each league in 2006 (data from



American League


                                                         Batting           Fielding                   Win Shares


 1.  Derek Jeter                                    28.0                 4.6                               33

 2.  Joe Mauer                                      21.3                 9.5                               31

 3.  David Ortiz                                   29.3                 0.1                               29

 4.  Manny Ramirez                             26.9                 2.1                               29

 5.  Justin Morneau                              25.5                 2.0                               28

 6.  Jermaine Dye                                23.7                 2.8                               27

 7.  Raul Ibanez                                   24.0                 3.1                               27

 8.  Jim Thome                                    25.9                 0.0                               26

 9.  Carlos Guillen                               21.5                 4.3                               26

10.  Michael Young                            18.5                 7.7                               26



National League


 1.  Albert Pujols                                 36.3                 2.4                               39

 2.  Carlos Beltran                               30.0                 8.3                               38

 3.  Lance Berkman                             31.7                 2.0                               34

 4.  Miguel Cabrera                             30.9                 2.8                               34

 5.  David Wright                                27.4                 4.3                               32

 6.  Ryan Howard                               29.8                 1.2                               31

 7.  Alfonso Soriano                            25.9                 3.6                               30

 8.  Jose Reyes                                     26.3                 3.1                               29

 9.  Mike Cameron                              21.2                 7.2                               28

10.  Chase Utley                                 23.2                 4.9                               28


As you can see, Derek Jeter had the best overall season in the American League in 2006 with 33 win shares although David Ortiz had the best hitting season with 29.3 win shares.


And in the National League, Albert Pujols had both the best overall season with 39 win shares and the best hitting season with 36.3 win shares.


Does this mean that Derek Jeter and Albert Pujols were the most valuable players in their leagues during the 2006 season?  Yes, it does.  But does that mean that they were chosen to receive the Most Valuable Player Awards (MVP) for 2006?  No, it does not.


As it turns out, Justin Morneau (#5 on our list above) was chosen the American League MVP and Ryan Howard (#6 on the list above) was chosen National League MVP.  

Michael Hoban, Ph.D is Professor Emeritus of mathematics at the City University of N.Y.  He has been an avid baseball fan for over 60 years and has become a serious baseball analyst, since joining SABR (Society for American Baseball Research) in 1998.  He is the author of five baseball books including:  DEFINING GREATNESS: A Hall of Fame Handbook (Booklocker, 2012)   BASEBALL'S COMPLETE PLAYERS (McFarland: 2000) and FIELDER'S CHOICE (Booklocker: 2003). 

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