New York Mets: Ranking Tom Seaver among MLB’s greatest pitchers

New York Mets starter and all-time great Tom Seaver has died yesterday. Where does he rank among the greatest pitchers of all time?

The death Wednesday of New York Mets legend Tom Seaver deprives Major League Baseball of one of the greatest pitchers in the game’s history.

Seaver won 311 games in a 20-season career mostly with the New York Mets and Cincinnati Reds. That record included a pair of 20-win seasons (25-7 in 1969 and 22-9 in 1975), three Cy Young Awards (1969, 1973, and 1975), the 1967 National League Rookie of the Year Award and 13 All-Star Game selections.

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He was elected to the Hall of Fame in 1992 with 98.8 percent of the votes, a record percentage at the time.

Assessing Seaver’s place among the game’s all-time great pitchers involves surmounting the usual problems related to cross-era comparisons – most of them focusing on the changing nature and styles of the game. But there is no question that Seaver belongs in the conversation.

When statisticians make such comparisons, they are generally careful to apply two separate but equal approaches, peak, and career assessments. The first looks at a player’s accomplishments in his prime; the second considers the full extent of a player’s career.

Sandy Koufax – brilliant between 1962 and 1966 but with a relatively short career — is the prime illustration of a peak performer. Warren Spahn – who won 363 games over 21 seasons and nine times led the league in complete games — is the prototypical career yardstick.

Both approaches are valid; they are simply different.

We will assess Seaver from both approaches utilizing several yardsticks that naturally adjust for cross-era and park-sensitive factors. Doing so ought to enable us to fairly place Seaver within the panoply of great pitchers from Cy Young forward to the present day.

Career WAR

Wins Above Replacement (WAR) is among the most widely understood of modern measuring tools. Briefly, it rates each player based on the number of “wins” his seasonal performance amounted to compared with a theoretical “replacement” player.

When Seaver retired he ranked sixth all-time in career WAR with a total of 106.0. The only five pitchers ahead of him at that time were Cy Young  (165.7), Walter Johnson (151.9), Kid Nichols (116.7), Grover Cleveland Alexander (116.0) and Lefty Grove (113.3.)

Since his retirement, only one pitcher – Roger Clemens (138.7) has surpassed Seaver’s total.

He continues to rank ahead of such fellow All-Stars as Greg Maddux, Randy Johnson, Christy Mathewson, Steve Carlton,  Nolan Ryan, and Spahn.

Seaver had two seasons with double-digit WAR (10.2 in 1971, 10.6 in 1973, meaning he improved his team’s win total by more than 10 games in those two seasons. Since Seaver’s New York Mets won the 1973 World Series after taking the NL East by just a game and a half, it’s easy to make the case that Seaver was the difference in the team’s World Championship season.

In 1969, Seaver’s most famous season,  he produced a 7.2 WAR. The New York Mets won the NL East by eight games. In that fall’s World Series against Baltimore, Seaver started twice, with a 1-1 record.

Career Win Probability Added

Win Probability Added is an updated version of WAR and similar in that it gauges each player’s contributions toward victory. The cautionary note regarding WPA is that it is based on play-by-play data, for which comprehensive data only exist back to 1973. Prior to that, the data is slightly less reliable, although still good.

Seaver’s career partly predates 1973; he was a rookie in 1967. Generally, though, the statistic favors him. Had the statistic existed when Seaver retired, he would have ranked third all-time in the category at 56.43 wins. Only Grove (82.99) and Spahn (57.56) would have ranked ahead of him.

Since then, three pitchers – Clemens 977.75), Greg Maddux (59.46), and Mariano Rivera (56.59) — have passed him.

Among the pitchers he ranks ahead of are Pedro Martinez, Randy Johnson, Carl Hubbell, and Jim Palmer. The closest current pitcher to Seaver is Clayton Kershaw, 11th on the career list at 44.49, about a dozen wins behind Seaver.

A raft of Hall of Fame pitchers from pre-Seaver days – among them Bob Feller, Grover Cleveland Alexander, Whitey Ford, Bob Gibson, and Juan Marichal – rank behind Seaver.

In 1973, Seaver’s seasonal WPA was 3.92. Again, given the slim margin by which New York persevered in the NL East, that’s more than enough to see Seaver as the key to the The New York Mets World Series championship.

Career Adjusted ERA

This is decidedly Seaver’s weakest category.

Adjusted ERA is simply a pitcher’s earned run average adjusted for park and era-related factors. It is expressed on a scale where 100 equals the rating of an average pitcher.

Seaver won three ERA titles – 2.82 in 1970, 1.76 in 1971, and 2.08 in 1973 – and had a career 2.86 ERA. But he tended to pitch in neutral to pitcher-friendly parks – Shea Stadium and Riverfront Stadium – and he did so in eras that were considered neutral to pitcher-friendly. For that reason, his Adjusted ERA of 127 may be less impressive than Seaver’s actual career numbers.

In fact, he ranks only in a 10-way tie for 51st place all-time on the career Adjusted ERA list.

His peers at 127 include some familiar names: Kevin Brown, Gerrit Cole, Bob Gibson, Roy Oswalt, and Curt Schilling. Others at that level are old-timers Nig Cuppy, Stan Coveleski, Sal Maglie, and Jack Pfeister.

The leaders in career adjusted ERA+ is generally not parallel to the WAR or WPA leaders. They include Mariano Rivera (205), who has a vast lead on runner-up Kershaw (158). Those two are followed in the top five by Pedro Martinez (154), Jacob DeGrom, and Jim Devlin (both 150).

The top 10 is filled out by Lefty Grove, Walter Johnson, and Hoyt Wilhelm, with Dan Quisenberry, Ed Walsh, and Smoky Joe Wood in a three-way tie for ninth, 10th, and 11th.

Peak Adjusted ERA+

Although there is no pre-set formula, peak ratings are generally based on a player’s scores for his five best consecutive seasons. To properly place Seaver on this list, we’ve compared his peak to the peaks of 25 pitchers who rate highest on Jay Jaffe’s JAWS rating system, 23 of the Hall of Famers. For the record, Seaver ranks eighth on Jaffe’s list.

Among the 25 pitchers assessed for their peak performance as measured by adjusted ERA+, Seaver ranks in a three-way tie for 11th place with a five-year average of 158. Those peak seasons are – to nobody’s surprise – 1969 through 1973.

He’s in excellent company at that level, matched up at 158 with fellow Hall of Famers Tim Keefe and Kid Nichols, both of them 19th Century greats.

When he retired, Seaver would have ranked seventh all-time on this list, surpassed only by Walter Johnson (206), Christy Mathewson (178), Grover Cleveland Alexander (176), Lefty Grove (173), and Bob Gibson and Cy Young (both 163). If you must trail some people, that’s a pretty strong grouping.

Since Seaver’s retirement, the list has undergone a shuffle. The current leaders are Pedro Martinez (227 between 1997 and 2001) and Greg Maddux. Randy Johnson and Roger Clemens have also nudged Seaver just outside the top 10.

Peak WAR

Seaver does less well in the better established WAR metric. His five-season peak average is 8.0, again between 1969 and 1973.

As strong as that score sounds, it’s actually been bettered by 17 of the 25 all-time greats who were assessed. The peak WAR leader is Walter Johnson, with an average WAR of 12.3 between 1912 and 1916.

The peak WAR list tends to favor old-timers who ran up spectacular numbers for one or two seasons under pitching conditions that would be outdated today. The rest of the top 10 is entirely populated by pitchers who were in their glory prior to World War II: Cy Young, John Clarkson, Old Hoss Radbourn, Kid Nichols, Tim Keefe, Pud Galvin, Jim McCormick, Grover Cleveland Alexander, and Christy Mathewson.

For that reason, peak WAR may be considered a somewhat suspect rating tool for purposes of cross-era comparison.

Among pitchers who starred since the start of the Lively Ball Era in 1920, Seaver ranks eighth in peak WAR, behind Lefty Grove (9.2), Robin Roberts, Pedro Martinez. Bob Gibson, Randy Johnson, Roger Clemens, and Phil Niekro.

Considering pitchers who worked only since the start of the expansion era in 1960, Seaver’s 8.0 ranks sixth, trailing only Martinez (8.58 between 1997 and 2001), Gibson, Johnson, Clemens, and Niekro.