JAWS and the 2017 Hall of Fame ballot: An introduction to JAWS

The 2017 Hall of Fame ballot is out, but before we dive into discussion of the candidates, let's go over the stat that will guide our debates: JAWS.

It’s time to tackle the Baseball Writers' Association of America's 2017 Hall of Fame ballot, which was released last Monday, with 19 newcomers—headed by Ivan Rodriguez and Vladimir Guerrero—joining 15 holdover candidates. For the 14th year in a row, I’ll be evaluating each candidate’s career in light of both the popular perception of his candidacy and a sabermetric reckoning via my JAWS system. But rather than crowding each evaluation with a description of my system, I’ll lay out the nuts and bolts in this space so that readers can refer back to it as needed.

For the uninitiated, JAWS is short for Jaffe Wins Above Replacement Score. Like the famous cinematic shark, the catchy, self-referential acronym (introduced a year after the system’s debut) generally elicits screams at the first hint of its approach, as not everybody can withstand this deep dive into the debate over who is worthy of Cooperstown. But if you’re somebody who does like to partake in the discussion and chew on the candidacies, JAWS is for you.

JAWS is a tool for measuring a candidate’s Hall of Fame worthiness by comparing him to the players at his position who are already enshrined. It uses the baseball-reference.com version of Wins Above Replacement to estimate a player's total hitting, pitching and defensive value while accounting for the wide variations in scoring levels that have occurred throughout the game's history and from ballpark to ballpark. A player's JAWS is the average of his career WAR total and that of his peak, which I define as his best seven years. All three are useful for comparative purposes, as Hall of Famers come in different shapes and sizes. Some—such as Hank Greenberg, Ralph Kiner, Sandy Koufax and Jackie Robinson—dominated over periods of time cut short by injuries, military service or the color line. Others—such as Eddie Murray, Don Sutton and Dave Winfield—showed remarkable staying power en route to major milestones. It’s a misconception that every Hall of Famer must do both to be worthy of a bronze plaque in Cooperstown. If you’re using Babe Ruth, Ted Williams or Willie Mays as your yardstick, the institution will become a tomb, sealed off because nobody measures up in their wake.

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For the purposes of comparison, players are classified at the position where they accrued the most value, which may be different from where they played the most games, particularly as players tend to shift to positions of less defensive responsibility—and thus less overall value—as they age. As an example, think Ernie Banks at shortstop (54.8 WAR in 1,125 games there from 1953 to '61) as opposed to first base (12.8 WAR in 1,259 games there from '62 to '71). A small handful of enshrined players with fewer than 10 years of major league service, including pioneers and Negro Leaguers, are excluded from the calculations; Satchel Paige and Monte Irvin, for example, had major league careers too short to use as yardsticks for non-Negro League players.

The stated goal of the JAWS system is to improve the institution's standards, or at least to maintain them by identifying and (hopefully) admitting players at least as good as the average Hall of Famer at the position. Setting a lower bar than that would not only dilute the honor but also further strain a system that already has a significant bottleneck, in that the past few years have seen far more players who measure up than can fit on each voter’s 10-slot ballot. More than anything, the idea is to bring a measure of intellectual consistency to an often disorganized debate. Because of that, JAWS has gained a nice bit of exposure in recent years: It's been cited by actual Hall of Fame voters, included within MLB Network'stelevision coverage, and will grace the pages of a forthcoming book by yours truly.

When I began this series, I used Baseball Prospectus' version of Wins Above Replacement Player, but the 2017 ballot marks my fifth year using Baseball-Reference’s version of WAR. Site owner Sean Forman aided the process by creating several handy tools, including JAWS data on each player page and sortable positional leaderboards. B-Ref also has other great tools useful to any Hall of Fame discussion, including past voting results and projected future ballots.

For all that it includes, JAWS doesn’t incorporate everything that goes into a player’s Hall of Fame case. The system makes no attempt to account for postseason play, awards and other honors, league leads in important categories, career milestones and historical importance; much of that is better handled via the Bill James Hall of Fame Standards and Hall of Fame Monitor metrics. That information is all germane to the Hall of Fame discussion and can shade an argument for or against a player whose credentials are otherwise borderline, so I’ll incorporate it into my full evaluations.

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My system owes a great deal of inspiration to James's Historical Abstracts, both the 1985 original—which planted the career/peak distinction in my mind—and the 2001 version, which weighted a player's best seasons (using Win Shares) to produce a somewhat more transparent means of combining career and peak into a single ranking. In JAWS, a player's best seasons are effectively double-counted—an appropriate strategy given research into pennants added and the premium value of star talent, in that individual greatness can have a non-linear effect on team results, both in the standings and on the bottom line.

Here are the current positional standards, which are virtually the same as last year’s except at catcher and centerfielder following the 2016 elections of Mike Piazza and Ken Griffey Jr., though other positions may have moved a decimal point or two.

position	number	career war	peak war	jaws
SP	62	73.9	50.3	62.1
RP	5	40.6	28.2	34.4
C	14	52.7	34.2	43.4
1B	19	65.9	42.4	54.2
2B	20	69.3	44.5	56.9
3B	13	67.5	42.7	55.1
SS	21	66.7	42.8	54.8
LF	19	65.1	41.5	53.3
CF	19	71.1	44.5	57.8
RF	24	73.2	43.0	58.1
CI (1B/3B)	32	66.0	42.4	54.2
MI (2B/SS)	41	68.0	43.7	55.9
OF	62	70.1	43.0	56.5
CO (1B/3B/LF/RF)	75	67.9	42.2	55.1
MID (C/2B/SS/CF)	74	65.9	42.2	54.0
All Hitters	149	67.1	42.2	54.6

As with the past four election cycles I’ve covered for SI.com, I will devote individual articles to the top new and returning candidates, updating my previous work to ensure that it reflects their most recent ballot results as well as any changes to WAR and JAWS. I'll also devote shorter writeups to lesser newcomers with no shot at election and batch several of those together. While it's true that I could easily skip the likes of Melvin Mora and Tim Wakefield, I'm among those who feel that a player's appearance on the ballot itself is worth at least a brief valedictory, and I'm not about to break my Cal Ripken-like streak of covering every candidate.

In my next post, I’ll begin rolling out the top returning candidates. We’ll be onto the new ones soon as well.