The bulk of this column was originally published March 23, 2004, but with Bobby Crosby heading to the disabled list with broken ribs, I thought it was worth revisiting.
In the history of baseball, there have been 116 Rookie of the Year winners. One in both 1947 and 1948, and then two each season from 1949-2004 (with a couple of ties thrown in). The list of winners — starting with Jackie Robinson in 1947 and ending with Jason Bay and Bobby Crosby last year — is as impressive as it is long, with numerous Hall of Famers spread throughout.
One thing that has long been associated with rookies, particularly Rookie of the Year winners, is the “sophomore slump.” During the very press conference in which he was given the 2002 American League Rookie of the Year award, Eric Hinske broached the subject:
Just because I had a good rookie season doesn’t mean I’m going to rest on my laurels. Hopefully I can avoid the sophomore slump.
Sadly, Hinske couldn’t avoid it. He missed nearly 40 games with injuries in 2003 and saw his numbers drop across the board. He went from 22 Win Shares in his rookie season to just 12 in his second year, and his OPS+ dropped from 124 to 96.
Similarly, the 2003 Rookie of the Year winners, Angel Berroa and Dontrelle Willis, both declined in their second seasons. Berroa saw his OPS+ drop from 96 in 2003 to 83 last year, and he struggled so much early on that the Royals demoted him to Double-A for two weeks in the middle of the season. Willis’ ERA ballooned from 3.30 in 2003 to 4.02 last year, and his strikeout rate and strikeout-to-walk ratio also dropped off significantly. Berroa and Willis each had 10 Win Shares in their sophomore seasons, after posting 16 and 14 Win Shares as rookies, respectively.
Is what happened to Hinske, Berroa, and Willis commonplace? Does the sophomore slump truly exist? To find out, I compiled the numbers of every Rookie of the Year winner in baseball history, and I think the findings are interesting. Prior to looking up the actual numbers, I tried to decide what I thought I would find. I tossed around a few ideas in my head and decided that … well, I wasn’t quite sure.
On one hand, you might expect a Rookie of the Year winner to decline in his second year for several reasons. First, he obviously had a very good season as a rookie, which leaves plenty of room for decline. Second, it is likely that in winning the award the player stayed very healthy, which again leaves plenty of room for decline the next season. I think regression to the mean is the technical term.
On the other hand, most Rookie of the Year winners are very young, which means you would normally expect them to improve, not decline. In other words, if you took a 30-year-old who played very well and stayed healthy, you might expect less of him in the next season. But you might not expect the same decline from a 23-year-old, right? I wasn’t sure, so I let the numbers tell me what the truth is.
First, a little information about the 116 Rookie of the Year seasons …
According to Win Shares, the top Rookie of the Year season came from Dick Allen in 1964. At 22 years old, Allen played in all 162 games for the Phillies, batting .318/.382/.557 with 29 homers, 38 doubles, 13 triples, 91 RBIs, and 125 runs scored. He ranked fifth in the NL in batting average, seventh in on-base percentage, and third in slugging percentage. Allen led the league in runs scored, total bases, triples, and extra-base hits, and finished seventh in the MVP balloting. To put that in some context, his rookie season was worth 41 Win Shares, which is one more than Albert Pujols had last season.
The worst Rookie of the Year season of all-time is a tie, between Ken Hubbs in 1962 and John Castino in 1979. Hubbs hit .260/.299/.346 in 160 games for the Cubs, which comes out to an OPS+ of 70 (for comparison, Rey Sanchez has a career OPS+ of 69). Castino played 148 games for the Twins and batted .285/.331/.397, which was good for an OPS+ of 93. Both Hubbs and Castino had nine Win Shares in their rookie years.
Of the 116 total winners, 87 were hitters and 29 were pitchers. By those numbers, pitchers seem under-represented, receiving just 25% of the awards. In recent years, however, pitchers have won slightly more often. Since 1995, six pitchers have won the award, compared to 14 hitters. The average Rookie of the Year season has been worth 19 Win Shares, so last year’s winners were both below average in that respect; Bay had 18 Win Shares, while Crosby had 13.
So, now that we know a little bit about the 116 Rookie of the Year winners, let’s take a look at how they performed in their sophomore seasons. Since Bay and Crosby are just starting their second seasons, they are excluded from this little study. That leaves 114 players left to look at (using Win Shares). Of those 114 Rookie of the Year winners …
- 73 declined in their second year (64.0%)
- 37 improved in their second year (32.5%)
- 4 stayed the same in their second year (3.5%)
Here are the largest gainers:
ROY YR1 YR2 +/- Dwight Gooden 1984 18 33 +15 Cal Ripken Jr. 1982 23 35 +12 John Castino 1979 9 18 +9 Bill Virdon 1955 14 21 +7 Eddie Murray 1977 21 28 +7 Raul Mondesi 1994 15 22 +7 Herb Score 1955 19 26 +6 Tony Oliva 1964 27 33 +6 Darryl Strawberry 1983 18 24 +6 Jeff Bagwell 1991 23 29 +6
Dwight Gooden had the 14th-best season of any Rookie of the Year pitcher and still managed to nearly double his Win Shares the next year. After going 17-9 with a 2.60 ERA in 218 innings as a rookie in 1984, Gooden was absolutely amazing in his sophomore season, going 24-4 with a 1.53 ERA and 268 strikeouts in 276.2 innings on his way to the 1985 National League Cy Young award.
Like Gooden, Cal Ripken Jr. was great as a rookie and then incredible as a sophomore. After hitting .264/.317/.475 with 28 homers, 32 doubles, 93 RBIs, and 90 runs scored as a rookie, Ripken Jr. was the American League MVP in his second year, batting .318/.371/.517 with 27 homers, 47 doubles, 102 RBIs, and 121 runs scored. Our old friend Castino, co-owner of the worst Rookie of the Year season ever, doubled his Win Shares in Year 2, hitting .302/.336/.430 with 13 homers and a 103 OPS+.
In all, just two Rookie of the Year winners — Gooden and Ripken Jr. — improved by at least 10 Win Shares in their sophomore season. That is vastly different than the number of huge declines:
ROY YR1 YR2 +/- Mark Fidrych 1976 27 7 -20 Carl Morton 1970 21 4 -17 Walt Dropo 1950 21 5 -16 Joe Black 1952 20 4 -16 Carlton Fisk 1972 33 17 -16 Rick Sutcliffe 1979 16 0 -16 Willie Mays 1951 19 5 -14 Stan Bahnsen 1968 23 9 -14 Joe Charboneau 1980 15 1 -14 Kerry Wood 1998 14 0 -14
And that’s just the “top” 10. In total, there were 26 Rookie of the Year winners who declined by at least 10 Win Shares in their second season, with Mark Fidrych leading the way.
The quirky right-hander had the most Win Shares of any Rookie of the Year pitcher, with 27 in 1976. “The Bird” went 19-9 with a 2.34 ERA in 250.1 innings for the Tigers, becoming one of the most popular players in baseball. At 21, he finished second in the AL Cy Young balloting, led the league in ERA, and started the All-Star game. Then, in March of 1977, Fidrych injured his knee while shagging fly balls in the outfield. He returned later in the year and wound up going 6-4 with a 2.89 ERA in 81 innings during his sophomore season, a dropoff of 20 Win Shares from his rookie year. He later had severe arm problems and wound up winning just four major-league games after his second season.
Like Fidrych, Kerry Wood took baseball by storm as a 21-year-old, going 13-6 with a 3.40 ERA and an amazing 12.6 strikeouts per nine innings. In just his fifth major-league start, Wood tied Roger Clemens‘ all-time record for strikeouts in a game, with 20 in a one-hitter against the Houston Astros. Also like Fidrych, Wood’s sophomore season was decimated by injuries. After having 14 Win Shares as a rookie in 1998, Wood didn’t pitch a single inning in 1999 as a result of undergoing Tommy John surgery.
Rick Sutcliffe saw an even bigger dropoff than Wood from Year 1 to Year 2, going from 16 Win Shares as a rookie to zero as a sophomore. Unlike Wood, Sutcliffe pitched plenty in his second year (some Dodgers fans might say too much, even), going 3-9 with a 5.56 ERA in 110 innings.
In addition to the “raw” numbers above, another way to look at this would to be use the percentage of Win Shares lost or gained. Here are the largest gainers:
ROY YR1 YR2 +/- John Castino 1979 9 18 +100.0 Dwight Gooden 1984 18 33 +83.3 Cal Ripken Jr. 1982 23 35 +52.2 Bill Virdon 1955 14 21 +50.0 Raul Mondesi 1994 15 22 +46.7 Bob Horner 1978 14 19 +35.7 Eddie Murray 1977 21 28 +33.3 Darryl Strawberry 1983 18 24 +33.3 Ken Hubbs 1962 9 12 +33.3 Herb Score 1955 19 26 +31.6
Most of the usual suspects. Castino shows up once again, leading the way by doubling his Win Shares in Year 2.
The largest decliners:
ROY YR1 YR2 +/- Rick Sutcliffe 1979 16 0 -100.0 Kerry Wood 1998 14 0 -100.0 Bob Hamelin 1994 12 0 -100.0 Joe Charboneau 1980 15 1 -93.3 Albie Pearson 1958 15 2 -86.7 Sandy Alomar Jr. 1990 15 2 -86.7 Carl Morton 1970 21 4 -81.0 Joe Black 1952 20 4 -80.0 Al Bumbry 1973 17 4 -76.5 Walt Dropo 1950 21 5 -76.2
As you can see, Sutcliffe and Wood are joined by Bob Hamelin as the only three Rookie of the Year winners to have zero Win Shares in their second season. Hamelin won the 1994 AL Rookie of the Year after batting .282/.388/.599 with 24 homers and 25 doubles in 101 games for the Royals. He ranked fifth in the AL in slugging percentage and OPS, ninth in homers, and sixth in OPS+. Hamelin then dropped to .168/.278/.312 in 72 games the next year.
Overall, sophomore-year declines dominate the study. Sixty-four percent of the Rookie of the Year winners declined in their second season and just 32.5% improved. Of the 73 players who declined as sophomores, 54 of them saw their Win Shares drop by at least 25%, 23 of them by 50% or more, and 10 of them by at least 75%. On the flip side, just 11 players increased their Win Shares by at least 25% in Year 2 and only four improved by 50% or more. Only Castino and Gooden improved by 75% or more as sophomores.
Decline Improve >75% 10 2 >50% 23 4 >25% 54 11 >10% 66 26
In total, the average Rookie of the Year winner from 1947-2003 dropped from 19 Win Shares in their rookie season to 16 Win Shares in their sophomore year, a decrease of 20%. As a group, hitters declined far less than pitchers, going from 20 Win Shares in Year 1 to 17 Win Shares in Year 2, a drop of 15%. Pitchers declined an average of 33%, from 18 Win Shares as rookies to 12 Win Shares as sophomores.
The “sophomore slump” is a cliche at this point and there are far more complicated (and mathematical) reasons for it occuring than the nickname suggests. At the same time, the fact is that it is “real” in the sense that the majority of Rookie of the Year winners decline in their sophomore seasons. Crosby’s broken ribs likely leave it up to Bay to break the trend. He is off to a decent start, hitting .300/.344/.333 through seven games, and needs 19 Win Shares this year to do it.