The end of March is a time of great anticipation in the baseball world. Fans are nearly as anxious as the players to see the teams head north and start getting some hard answers to the questions that surround their favorite ball clubs. Since veterans have generally established expected levels of performance, much of the buzz and uncertainty surrounds rookies who have survived the spring sifting.

For franchises like Arizona (John Patterson and Lyle Overbay), Philadelphia (Marlon Byrd) and the Yankees (Hideki Matsui), the ability of their prized rookies to make the jump to the majors may be the difference in winning the division. In Cleveland (Travis Hafner and Brandon Phillips) and on Chicago’s North Side (Hee Choi), youngsters are centerpieces as the teams try to return to competitiveness. Meanwhile, Kansas City (Angel Berroa) and Tampa Bay (Rocco Baldelli) are banking on new faces to provide some optimism for the future. Regardless of the team’s near-term goals, their chances of achieving them will be buoyed if their first-year players make a big splash. While impatiently waiting for the words “Play Ball” to be yelled out Sunday evening in Anaheim, I decided to determine what rookies have turned in the greatest “impact” seasons in history.

A player’s season needs to be evaluated in the context in which it occurred to determine its impact, since identical statistical lines from two different environments (e.g. 1968 National League versus 2000 American League) can have vastly divergent values. To accurately measure the impact of a rookie’s performance, it must be compared only to other players in the same league within the same year. And since analysts have made great strides in quantifying defense the past few years, positional value and a player’s defensive performance should also be included in the evaluation.

Fortunately for both of us, I didn’t have to invent the wheel. WARP (Wins Above Replacement Player) was used as the measurement tool, and is listed on the BP Player Cards. Specifically, I used WARP1, which is defined as, “The number of wins this player contributed above what a replacement level hitter, fielder and pitcher would have, with adjustments for only within the season.” Defense is included in the WARP1 numbers, as well as adjustments for park effects.

I decided to limit the study to seasons since 1950 for a number of reasons. Major League Baseball at long last began to remove its “Whites Only” signs in 1947. Though all 16 franchises wouldn’t break the color line until 1959, by 1950 desegregation had established a firm toehold in the game. Also, there have been no World Wars (knock on white ash) since the first half of the 20th Century. During the war years, players who should have been bouncing around the Three-I League were instead pulling on big league uniforms. Finally, there were dramatically less strikeouts in the early years of professional baseball, which causes more defensive runs to be distributed among the position players. This increased defensive credit can lead to some very high WARP1 numbers.

For the purposes of the study, “rookies” are defined by the current MLB playing time standards-less than 130 at-bats for position players and less than 50 innings pitched for pitchers. I dropped the service time requirement of no more than 45 days on the active roster because that information isn’t readily available. As a result, there will be players on the lists who were technically not rookies for the year given.

Straight-line adjustments were made to the WARP1 figures for selected seasons to put everybody on a level 162-game playing field. The specific years involved were 1950 through 1960 (154-game schedule), and the strike-affected years of 1972, 1981, 1994 and 1995.

OK, enough with the methodology-onto the results:

Top 25 Impact Seasons by Rookie Hitters

Year  Player               Team  WARP1
2001  Suzuki, Ichiro        SEA   11.1
1964  Allen, Dick           PHI   10.6
1975  Lynn, Fred            BOS   10.4
1950  Rosen, Al             CLE   10.3
1993  Salmon, Tim           CAL   10.1
1964  Oliva, Tony           MIN   10.0
1993  Piazza, Mike          LAD    9.8
1977  Page, Mitchell        OAK    9.5
1972  Fisk, Carlton         BOS    9.4
1995  Cordova, Marty        MIN    9.4
2001  Pujols, Albert        STL    9.3
1959  Pinson, Vada          CIN    9.2
1972  Baker, Dusty          ATL    9.2
1965  Morgan, Joe           HOU    9.1
1997  Garciaparra, Nomar    BOS    9.1
1970  Grabarkewitz, Billy   LAD    8.8
1987  McGwire, Mark         OAK    8.8
1987  Seitzer, Kevin        KCY    8.8
1971  Garr, Ralph           ATL    8.7
1964  Hart, Jim Ray         SFG    8.6
1973  Ferguson, Joe         LAD    8.6
1972  Grich, Bobby          BAL    8.4
1977  Wills, Bump           TEX    8.3
1966  Agee, Tommie          CHW    8.2
1991  Bagwell, Jeff         HOU    8.2

Seattle’s most exciting Japanese import since terra-maki sits in the catbird seat with a 2001 campaign that won him both Rookie of the Year and MVP honors. The fact that Dick Allen‘s full-season debut finishes second may border on blasphemy for Phillie Phans who prefer to remember his 1964 wrecking machine instead of the team’s panicked late-September collapse. That year, Allen fashioned an offensive line that would look impressive in any era, let alone the pitching-dominated 1960s. However, Suzuki rises to the top on the strength of his play in the field, receiving credit for two dozen more fielding runs than Allen.

The Top 25 is filled with position players who went on to have solid, often spectacular, careers. The one obvious exception is Billy Grabarkewitz. Despite an underwhelming (.092/.145/.138) 34 games off the Dodgers’ bench in 1969, Grabarkewitz left Vero Beach as the utility infielder the next spring. A minor injury to second baseman Ted Sizemore in the second game of the season opened the door for Grabarkewitz, who suddenly started hitting like Roy Hobbs. Manager Walter Alston didn’t dare take him out of the lineup, carving out playing time around the infield. As late as the end of May, Grabarkewitz was batting over .400 with an OBP above .500, igniting a furious write-in campaign to elect “Billy G.” to the All-Star Game. Though the effort fell short, Grabarkewitz made the NL squad as a reserve. He cooled off dramatically the second half of the season, but still led the Dodgers in six offensive categories. The team created a full-time position for him by swapping Sizemore for Dick Allen (!) four days after the season ended. However, Grabarkewitz hurt his shoulder early in the 1971 campaign, an injury that eventually required surgery. He never saw regular action again, logging just 680 plate appearances (hitting .203/.328/.307) over the next five years before exiting the majors at age 29.

As for rookies who made a big impact on the mound:

Top 25 Impact Seasons by Rookie Pitchers

Year  Player               Team  WARP1
1953  Haddix, Harvey        STL    9.6
1981  Valenzuela, Fernando  LAD    9.3
1986  Eichhorn, Mark        TOR    9.2
1963  Peters, Gary          CHW    9.0
1976  Fidrych, Mark         DET    9.0
1980  Burns, Britt          CHW    8.3
1980  Corbett, Doug         MIN    7.8
1984  Gooden, Dwight        NYM    7.5
1955  Score, Herb           CLE    7.2
1975  Montefusco, John      SFG    7.1
1995  Nomo, Hideo           LAD    7.1
1972  Matlack, Jon          NYM    7.0
1974  Tanana, Frank         CAL    7.0
1967  Seaver, Tom           NYM    6.9
1968  Bahnsen, Stan         NYY    6.8
1975  Eckersley, Dennis     CLE    6.8
1981  Righetti, Dave        NYY    6.8
1957  Sanford, Jack         PHI    6.7
1962  Radatz, Dick          BOS    6.7
1977  Guidry, Ron           NYY    6.7
1984  Langston, Mark        SEA    6.7
1951  Rogovin, Saul         CHW    6.6
1973  Medich, Doc           NYY    6.6
1990  Appier, Kevin         KCY    6.5
1954  Sullivan, Frank       BOS    6.3
1970  Morton, Carl          MON    6.3

A recent thread on SABR-L discussed players who are remembered for a single play, like Fred Merkle. Harvey Haddix‘s career hasn’t been reduced to a ten second byte, but his name immediately brings to mind the 12 innings of perfect baseball he tossed on May 26, 1959 before ultimately losing the game. In fact, Haddix had a sturdy 14-year career despite not reaching the majors until age 26. However, like many of the pitchers listed above, his first year was his best. In 1953, Haddix ranked among the NL leaders in most major pitching categories on his way to becoming one of three hurlers (along with Bob Grim and Tom Browning) in the past 50 years to win 20 games as a rookie.

An irresistible combination of novelty, personality and performance caused Fernando Valenzuela and Mark Fidrych to trigger two of the more memorable crazes in the game’s history. After a spotless late-season cameo out of the bullpen in 1980, “Fernando-mania” fully flowered the following spring. Playing to packed houses, the “20”-year-old Valenzuela allowed just four runs while twirling five shutouts in his first eight starts before descending to a mortal level. The chubby lefthander became the first player to ever win the Rookie of the Year and Cy Young Award in the same season. It deserves mentioning that Valenzuela probably wouldn’t have ranked so highly on our list except for an upward adjustment because his season was shortened by the 1981 player’s strike.

You wouldn’t guess it looking at his final numbers, but Fidrych’s 1976 campaign was also effectively shortened. The last pitcher on the Tiger’s roster, he made just two appearances out of the bullpen the first five weeks of the season. However, once dropped into the starting rotation, Manager Ralph Houk made up for lost time by having Fidrych complete 24 of 29 starts, including back-to-back 11 inning contests where he threw an estimated 175 and 143 pitches. “The Bird” became a full-fledged phenomenon when a national television audience witnessed his manic mound antics in beating the Yankees in late-June. Although some argue that Fidrych couldn’t have sustained his success with such a low strikeout rate (3.7 K/9), he was consistently successful when healthy. Sadly, that didn’t last very long. Fidrych blew out his shoulder midway through the next season and never fully recovered.

Perhaps the biggest surprise is Mark Eichhorn‘s 1986 campaign checking in at No. 3. To stop the pain in an aching right shoulder and try to salvage a career, Eichhorn switched to a funky, low-sidearm motion after the 1984 season. Though his fastball barely crawled over 80 mph, his breaking pitches had tremendous movement and a slight hesitation in his new delivery disrupted the batter’s timing. A non-roster invitee to Spring Training in 1986, Eichhorn made the club and ended up throwing a staggering 157 innings out of Jimy Williams‘ bullpen. He fell five innings short of joining Hoyt Wilhelm (1952) as the only pitcher to win the ERA title working exclusively in relief.

Though not presented here, I determined the Top 100 impact seasons for rookie hitters and pitchers. The cutoff points were a WARP1 of at least 6.0 for hitters and 4.6 for pitchers. Something interesting appears when you sort the results by decade:


            # of Impact       # of Team-     Impact Rookies
Decade        Rookies          Seasons       per Team-Season
-------     -----------       ----------     ---------------
1950-59          17              160             .106
1960-69          22              198             .111
1970-79          26              246             .106
1980-89          17              260             .065
1990-99          19              278             .068
2000-02           2               90             .022


            # of Impact       # of Team-     Impact Rookies
Decade        Rookies          Seasons       per Team-Season
-------     -----------       ----------     ---------------
1950-59          19              160             .119
1960-69          21              198             .106
1970-79          21              246             .085
1980-89          19              260             .073
1990-99          17              278             .061
2000-02           4               90             .044

It seems clear that impact rookies, as defined by our measures, are becoming increasingly less common. This has been especially true in the new millennium. The past three seasons had only six, with Suzuki and Albert Pujols being joined by pitchers Rick Ankiel, Roy Oswalt, C.C. Sabathia and Rodrigo Lopez. While this may not indicate a lasting trend, only one other three-year period (1985-1987) since 1950 has as few as six entries in the Top 100 lists. Even if the first three years of this decade prove to be an aberration, it’s hard to envision the numbers climbing to the level of the 1970s.

A typical big league ball club in the 1950s could expect to have an impact rookie on its roster every four or five years. The data above indicates that over the past half-century the frequency has gradually decreased to once every 15 years. This development is likely due to some combination of the following:

  • Improved nutrition, conditioning and medical care has enabled veterans to extend their careers, creating fewer job opportunities for young players.
  • Larger contracts provide an obvious incentive for players to postpone retirement as long as possible. What ever happened to the notion that big money would cause players to retire sooner?
  • Time spent on the disabled list has been mounting for players of all age groups. WARP1 rewards playing time so long as you are above replacement level, so less time on the field means a lower WARP1 total.
  • As in every sport, the level of play in baseball keeps rising. This could necessitate a longer adjustment period once a player reaches the majors.
  • Teams shuttle prospects back and forth to the minors more than they used to, causing many newcomers to prematurely exhaust their rookie eligibility.
  • As various clauses tied to service time have been added to the Collective Bargaining Agreement, teams have more incentive to open the season rookie-free. Delaying a player’s arrival to The Show by a few months can set back their arbitration and free agency clocks.
  • The five-man rotation and increased bullpen usage has decreased the number of innings starting pitchers work. As mentioned before, WARP1 rewards playing time.

  • After remaining fairly stable for about 35 years, strikeouts began rising again in the mid-1990s. This reduces the number of fielding runs available to divide among position players. However, these runs don’t vanish-they boost the pitcher’s WARP1, so the net effect is quite small.

What implications does this have for baseball fans? Roto-geeks might want to tone down expectations for their favorite phenom. But besides that, there really aren’t any. Like the game between the lines, rookies entering Major League Baseball are better than ever. Circumstances have simply conspired to depress their Year One bottom lines. So sit back, relax and enjoy the season.

Thank you for reading

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