In The Fielding Bible I introduced a new way to quantify defensive contributions called the Plus/Minus System. The book covered every 2005 defensive player other than pitchers and catchers using Plus/Minus and a variety of other defensive metrics.
The Bill James Handbook 2007 published the Plus/Minus leaderboards for the 2006 season (adding pitchers for the first time) and the 2008 version will publish the Plus/Minus leaderboards for the 2007 season. But how about a preview now?
The recent All-Star Game tried to bring together 2007’s best players. Let's take a look at the best players from a defensive standpoint thus far this year. Here are the 2007 Plus/Minus defensive leaderboards (through games of Monday, July 16).
First Basemen
| Name | Team | PM |
| Albert Pujols | StL | +25 |
| Casey Kotchman | LAA | +13 |
| Ryan Klesko | SF | +10 |
| Kevin Youkilis | Bos | +8 |
| Ryan Shealy | KC | +8 |
Second Basemen
| Name | Team | PM |
| Chase Utley | Phi | +16 |
| Aaron Hill | Tor | +13 |
| Mark Ellis | Oak | +12 |
| Howie Kendrick | LAA | +10 |
| Brandon Phillips | Cin | +8 |
| Kaz Matsui | Col | +8 |
Third Basemen
| Name | Team | PM |
| Pedro Feliz | SF | +21 |
| David Wright | NYM | +15 |
| Scott Rolen | StL | +13 |
| Aramis Ramirez | ChC | +13 |
| Adrian Beltre | Sea | +12 |
Shortstops
| Name | Team | PM |
| Troy Tulowitzki | Col | +22 |
| Adam Everett | Hou | +17 |
| Jack Wilson | Pit | +12 |
| Omar Vizquel | SF | +12 |
| Jason Bartlett | Min | +12 |
Left Fielders
| Name | Team | PM |
| Shannon Stewart | Oak | +11 |
| Matt Holliday | Col | +10 |
| Geoff Jenkins | Mil | +9 |
| Adam Lind | Tor | +8 |
| Emil Brown | KC | +8 |
Center Fielders
| Name | Team | PM |
| Andruw Jones | AtL | +22 |
| Carlos Beltran | NYM | +16 |
| Curtis Granderson | Det | +14 |
| Coco Crisp | Bos | +13 |
| Alfredo Amezaga | Fla | +8 |
| Ryan Church | Was | +8 |
Right Fielders
| Name | Team | PM |
| Andre Ethier | LAD | +16 |
| Carlos Quentin | Ari | +10 |
| Austin Kearns | Was | +9 |
| Alex Rios | Tor | +8 |
| Magglio Ordonez | Det | +7 |
| Corey Hart | Mil | +7 |
Pitchers
| Name | Team | PM |
| Greg Maddux | SD | +5 |
| Jon Garland | ChW | +5 |
| Kameron Loe | Tex | +5 |
| Five Tied With | | +4 |
The worst defensive player thus far this year: Florida Marlins shortstop Hanley Ramirez at -23. Derek Jeter is a close second at -21.
By the way, I've been asked the same question many times: When will the next edition of The Fielding Bible come out? Answer: Not this year, but likely next year. The reason: We're working on a new book that will take time away from doing a Fielding Bible this year. The new book is called The Bill James Gold Mine. Keep an eye out for it next spring.
Short description of the Plus/Minus System:
The Fielding Bible contains a detailed explanation of the Plus/Minus System, but here is a summary.
The plus/minus figure of +25 for Albert Pujols means that he made 25 more plays than could be expected from an average first baseman. This +25 is determined by looking at each play hit in his direction and comparing what Pujols does with that play compared to all other first basemen.
Every time a fielder catches a ball and gets the out, he receives a fraction between 1 and 0. If it was a difficult play, he gets a larger fraction. An easy play, a smaller fraction. That fraction is determined by what percentage of times that same play is made by all players at that position, in the same location of the field, and on a ball hit just as hard. The higher the percentage (easier play), the lower the fractional award for the defensive play. The lower the percentage (harder play), the higher the factional award.
Every time a fielder fails to make the play, he gets a negative version of that same fraction.
We add up all these fractions and round the number to an integer to create their Plus/Minus at that position (some guys play multiple positions in one season). A final Plus/Minus number around zero indicates an average performance.