I've read a number of dissenting opinions in recent months on the Toronto Blue Jays daring offseason acquisition of Cy Young winner and best-selling author R.A. Dickey. A number of Dickey's detractors have cited concerns over his age and his transition to a far more dangerous division and league. If Dickey does manage to perform well for the duration of his contract with Toronto, however, he is certain to pass some historical milemarkers for players reaching their potential in the back end of their careers.

For a period of seven years from 2001-2009 Dickey was worth just 0.2 Wins according to Baseball-Reference. Dickey continued to struggle even after switching over to the knuckleball for the 2006 season, but at age 35 everything suddenly clicked for the right-hander.

Since then, Dickey has amassed a hefty 12 WAR in just three seasons. As you would probably expect, it is exceptionally rare for a player to post more WAR after the age of 35 than before. In fact, just eleven other pitchers in baseball history have exceed their pre-35 totals by at least 10 WAR afterward. Dickey, now 39, is the most recent.

Greatest WAR difference pre-35, post-34

Name Debut After 34 WAR Before 35 WAR WAR difference Phil Niekro 1964 62.0 29.7 32.3 Jack Quinn 1909 41.0 12.5 28.5 Hoyt Wilhelm 1952 36.1 11.3 24.8 Charlie Hough 1970 28.8 6.0 22.8 Jamie Moyer 1986 30.9 13.9 17.0 Johnny Niggeling 1938 16.9 -0.1 17.0 Randy Johnson 1988 57.8 40.8 17.0 Dazzy Vance 1915 37.0 23.5 13.5 Marv Grissom 1946 12.9 -0.3 13.2 Rip Sewell 1932 18.4 5.5 12.9 Ellis Kinder 1946 20.8 8.7 12.1 R.A. Dickey 2001 12.1 0.2 11.9

It should come as no surprise that four of the pitchers in this list-- Niekro, Wilhelm, Hough, and Niggeling-- were all knuckleballers as well. Age 35 seems to regularly usher in the beginning of a career plateau of sorts for knuckleballers. Not too long ago, a commenter at BTBS named "froston" posted this knuckleballer aging curve (using Fangraphs' RA9 Wins) verifying this impression.

Niekro is undoubtedly the best of these knuckleballers, posting an unimaginable 62 WAR after his age-34 season. Most of that was accomplished during a magnificent six year run from 1974-1979 where the Hall of Famer averaged a WAR of 7.6 per season in that time.

Charlie Hough was not quite the dominant brand of knuckleballer that Niekro had been a decade earlier, but his peak (also a six-year stretch from age-35 to age-40) was nearly just as impressive, posting an ERA+ of 119 and 4.4 WAR per season.

Hoyt Wilhelm did not begin his major-league career until he was 29 years old and still became a Hall of Famer. While Johnny Niggeling hadn't seen any MLB action until he was the ripe old age of 34, ultimately joining the 1944 all-knuckleball rotation in Washington.

Rip Sewell was not a knuckleballer, but did survive the latter part of his career on the strengths of his famous 'blooper' pitch. After a late start to his career at age-31, Sewell famously invented what we now know as the "eephus pitch" during wartime baseball in the 1943-44 seasons.

Niether Ellis Kinder nor Marv Grissom were known for a novelty pitch of any kind, but both pitchers did begin their careers at 31 years old, and managed to find success, one way or another, after turning 35.



Dazzy Vance and Randy Johnson, however, were both flame-throwers that only figured out how to pitch as they entered their 30s. In fact, beginning at the age of 35 Randy Johnson embarked upon a remarkable stretch of four consecutive seasons winning the National League Cy Young award.

Jamie Moyer makes this list out of not only as a matter of his indefatigable career endurance, but he too, learned to pitch as he aged. His post-35 seasons in a Mariner's uniform were easily the best of his career.

Position Players

For position players, however, the list is not nearly as impressive. Among all players having debuted since 1900, only two players managed five more WAR after 35 than before, yet neither was very successful in either half of their career.

Greatest position player WAR difference pre-35, post-34

# Name Debut After 34 WAR Before 35 WAR WAR difference 1 Bob Boyd 1951 5.4 0.2 5.2 2 Eddie Mayo 1936 3.9 -1.2 5.1 3 Chris Gomez 1993 0.5 -4.2 4.7 4 Tom Carey 1935 0.0 -4.3 4.3 5 Ray Berres 1934 -0.1 -4.3 4.2 6 Billy Hitchcock 1942 -1.1 -5.2 4.1 7 Dale Sveum 1986 0.3 -3.8 4.1 8 Chad Moeller 2000 -0.1 -4.1 4.0 9 Myril Hoag 1931 -0.4 -4.4 4.0 10 Moe Berg 1923 -0.7 -4.6 3.9

Bob Boyd spent considerable time in the Negro Leagues before finally making the transition to the majors, which is likely the only reason he makes this list. At age 31, Boyd became the first black player to play for the Chicago White Sox. His time on the south side was spent mainly as a pinch hitter before finally given a chance to excel with real playing time in Baltimore at age 37.

Eddie Mayo had a very unsuccessful run in the major leagues from age 26-28 amassing a negative 0.6 WAR in that time. After a five year run in the Pacific Coast league, Mayo was finally given a chance to shine during war time for the Philidelphia Athletics. His career reached its greatest point in 1945 where his 4.1 WAR for the Detroit Tigers was good enough for the Sporting News to select him as Most Valuable Player that season.

Chris Gomez is the most recent player to meet the criteria of this phenomenon debuting in 1993 for the Tigers. Gomez essentially personified the concept of replacement level for most of the duration of his time in the majors, but was able to muster more value (or less negative value) in the last three seasons of his career as a utility infielder than as a full time shortstop in his younger days.

Tom Carey is an interesting case because in his six plate appearances after his 35th birthday, he managed to do very little damage to his team. This was very much unlike the previous six seasons of his career, however, in which he had been worth -4.3 WAR. In fact, at least seven of these ten position players make the list for the same reasons (with the possible inclusion of Gomez as well). By simply not playing very much after age 35, they earned "more" WAR than they had for their whole career. No WAR, after all, is far better than negative WAR.

Moe Berg was a spy.

Pitchers vs Hitters

We often expect pitchers to be less likely to exceed in the latter days of their careers than their position player counterparts. This assumption is probably based on the disproportional amount of injuries that appear to vex pitchers more often.

But throughout history Father Time seems to have been more kind to pitchers looking for second acts on the baseball diamond than it has been for hitters. And while this is not just true for knuckleballers, it certainly seems especially true for that special brand of pitcher of which R.A. Dickey may be the last representative.

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James Gentile writes about baseball at Beyond the Box Score and The Hardball Times. You can follow him on twitter @JDGentile.