Just How Good is Mariano Rivera?

“Mariano Rivera is the best reliever in baseball history.”  If I were to make such a claim, there would surely be some fans who would agree with me and many who would not.  And, of course, all would want to know on what basis I made such a claim.

Bill James’ Win Shares system is the most comprehensive tool available to understand how good a seasona player had.  It includes offensive and defensive contributions and adjusts for all relevant factors.  The CAWS Career Gauge (Career Assessment/Win Shares) uses win shares to measure how good a careera player has had.  The CAWS Gauge is based on a player’s core value (his ten best seasons) plus additional credit for his other seasons.  It is an objective tool which attempts to assess career value.  But in attempting to measure the career value of a relief pitcher, of course, we encounter some special difficulties.

In trying to establish reasonable benchmarks for Hall of Fame numbers, I naturally came up against the question: Since a relief pitcher who has never been a starter will normally pitch many fewer innings than a starting pitcher, how are you going to determine whether a relief pitcher has HOF numbers?  Obviously, the same standards cannot apply for a starting pitcher and a relief pitcher (not to mention a position player).

In wrestling with this question, I looked at the careers of all the great relief pitchers to try to establish a benchmark that would recognize the best – but would not be “too easy.”  And I believe that I have accomplished this task.

Consider the following statement.  Through the 2009 season, there have only been five pitchers in the modern era (since 1920) who have achieved a CAWS score of 150 while pitching fewer than 1700 innings.Here are those pitchers.  (I have included Rollie Fingers because he was so close to 1700.)  IP is innings pitched, CWS is career win shares, CV is core value (the win shares for the ten best seasons) and CAWS is the CAWS score [CAWS = CV + .25(CWS – CV)].

So, the CAWS Gauge has established the 1700/150 benchmark as the standard for “pure” relief pitchers to have HOF numbers.  And, as you can see, none of these pitchers comes anywhere close to what Mariano has achieved so far in his career – even though Bruce Sutter and Rollie Fingers are both in the Hall of Fame.  The Gauge suggests that these are the only pure relievers who have posted obvious HOF numbers during their careers – and all should be in the Hall.

Take a look at Lee Smith.  He is still on the BBWAA Hall of Fame ballot.  In 2010, he got 47% of the vote.  Hopefully, that means that within the next few years he may be inducted and claim his rightful place in Cooperstown.

Please note that some great relievers are not included here such as Hoyt Wilhelm, Dennis Eckersley and Goose Gossage.  We must recognize that some relievers were starting pitchers for some part of their careers and cannot be judged by the same standard as a pure relief pitcher (those who were never starters).  Each of these three outstanding relievers (Wilhelm, Eckersley and Gossage) pitched many more than 1700 innings during their careers.  And so, the CAWS Gauge has established a different benchmark which shows that all three did indeed post Hall of Fame numbers during their careers.

Consider the numbers for the following outstanding relief pitchers at the end of  2009.

As you can see, these two relievers are closing in on the CAWS benchmark of 150 but are not quite there yet.  Trevor Hoffman, of course, is the major league “saves leader.”  It looks like each of them may reach the benchmark in 2010.

Finally, in case you are wondering about some other pure relievers, here are the numbers for some of the best ever.  Note that none of them achieved the 150 CAWS benchmark.

The CAWS Career Gauge attempts to tell us in a purely objective manner which players posted Hall of Fame numbers during their careers.  And looking at the numbers above, you can see why I feel very comfortable in suggesting that Mariano Rivera is the best “pure” reliever in baseball history.

If anyone would like to get a free e-copy of Professor Hoban’s 100-page monograph: A HOF HANDBOOK: Who Belongs and Who Does Not ,  just drop a note to mike_hoban@msn.com .