Rookies

May 28, 2013

            I recently had the following question in "Hey, Bill":

Bill --If you were to take the average player's rookie season (i.e., the season that the player last qualified for ROTY award), how much improvement will there be by that player's peak season? Is it anything like useful to make a remark like, "Player X has 15 WS in his rookie year--we can expect him, on average, to have a peak season at some point of 25 WS"? If one season isn't enough, at what point  would we have enough seasons to make a useful general prediction as to eventual peak? After 1500 PA, say?

 

                To which I replied, at the time:

 

Any answer you could give, I think you'd have to give with numerous qualifications, but let me see what I can do.    First, let's exclude pitchers, since a very high percentage of rookie pitchers are unable to sustain the workload, and basically burn out after one season.    Second, we'd have to exclude players who get a full shot as a rookie, but don't truly establish the level of ability necessary to keep a job.  

 

From that point on, you'd get very different answers from a 21-year-old rookie than from a 25-year-old rookie.   I'll try to do some relevant research and edit this answer later on.

 

 

Ok, I have done some research here, so let me report on that. . .I thought the question was worthy of a little work.    I have a spreadsheet of career records. ..a kind of a "spreadsheet encyclopedia" that I use for projects like this.   I took that file, and eliminated from it:

 

1)  All players who played before 1950 (even one game before 1950), and

2)  Players who have played since 2011 (2011, 2012 or 2013), since those player may not yet have complete careers.

3)  All players who played less than 800 games in their careers.

 

This third elimination creates a major selection bias in the data, which makes these players who are studied here quite different from all rookies, and limits our ability to generalize what we learn from doing this.   (On the other hand, not restricting the study group would cause other problems which, in my judgment, would be much worse, so. . ..six of one, half-dozen of the other.    Doing the study this way, you learn quite a bit but you can’t generalize it reliably because of the selection bias.   Doing the study the other way you wouldn’t learn anything to begin with.)  

 

Anyway, I limited the data to players who played 800 games, so. . Al Weis is in, Rick Leach is out.   You have to draw a line somewhere.   To illustrate what I have done, let’s take all players who were rookies at the age of 18.

Since 1950 there have been three players who played 800 games and whose last rookie season was at age 18:   Wayne Causey (1955), Ed Kranepool (1963) and Robin Yount (1974).     This is what those three players did in their first seasons:

 

 

First

Last

YEAR

G

AB

R

H

2B

3B

HR

RBI

BB

SO

SB

CS

Avg

OBA

SPct

OPS

Wayne

Causey

1955

68

175

14

34

2

1

1

9

17

25

0

1

.194

.269

.234

.504

Ed

Kranepool

1963

86

273

22

57

12

2

2

14

18

50

4

2

.209

.256

.289

.545

Robin

Yount

1974

107

344

48

86

14

5

3

26

12

46

7

7

.250

.273

.346

.619

 

 

                And here is that with the average performance of the three:

 

First

Last

YEAR

G

AB

R

H

2B

3B

HR

RBI

BB

SO

SB

CS

Avg

OBA

SPct

OPS

Wayne

Causey

1955

68

175

14

34

2

1

1

9

17

25

0

1

.194

.269

.234

.504

Ed

Kranepool

1963

86

273

22

57

12

2

2

14

18

50

4

2

.209

.256

.289

.545

Robin

Yount

1974

107

344

48

86

14

5

3

26

12

46

7

7

.250

.273

.346

.619

                                     
   

1964

87

264

28

59

9

3

2

16

16

40

4

3

.223

.266

.302

.568

 

 

                On average, the 18-year-olds hit .223 with a .568 OPS in their rookie season.      In their second seasons, they improved to an average of .255 with a .667 OPS:

 

First

Last

YEAR

G

AB

R

H

2B

3B

HR

RBI

BB

SO

SB

CS

Avg

OBA

SPct

OPS

Wayne

Causey

1956

53

88

7

15

0

1

1

4

8

23

0

0

.170

.237

.227

.464

Ed

Kranepool

1964

119

420

47

108

19

4

10

45

32

50

0

1

.257

.310

.393

.703

Robin

Yount

1975

147

558

67

149

28

2

8

52

33

69

12

4

.267

.307

.367

.674

                                     
   

1965

106

355

40

91

16

2

6

34

24

47

4

2

.255

.301

.366

.667

 

                They relapsed a little in their third seasons:

 

First

Last

YEAR

G

AB

R

H

2B

3B

HR

RBI

BB

SO

SB

CS

Avg

OBA

SPct

OPS

Wayne

Causey

1957

14

10

2

2

0

0

0

1

5

2

0

0

.200

.471

.200

.671

Ed

Kranepool

1965

153

525

44

133

24

4

10

53

39

71

1

4

.253

.303

.371

.675

Robin

Yount

1976

161

638

59

161

19

3

2

54

38

69

16

11

.252

.292

.301

.593

                                     
   

1966

109

391

35

99

14

2

4

36

27

47

6

5

.252

.301

.332

.632

 

                Here we have a choice. .. here I had a choice, actually; you are pretty much stuck with the choices that I made.    Wayne Causey was a Bonus Baby with the Baltimore Orioles in ’55 and ’56.    The rules of the time required that a player getting a decent bonus had to spend two years on the major league roster (to discourage the signing of players to large bonuses), but after two years the player could go out to the minor leagues.    Causey spent his two seasons with the Orioles, then went to do his minor league work, and did not play in the majors in 1958, 1959 or 1960, just becausey.    

                I could, then, have grouped Causey’s next major league season either as his fourth major league season, third season after the rookie season, or as his age-24 season, grouping him with Kranepool in 1969 and Yount in 1980.    I decided to group him with other players playing their fourth season, third season after the rookie year.    It doesn’t ordinarily matter much, because most players don’t have three-year gaps in their careers, and the results you would get from grouping them one way would be essentially the same as the results you would get from grouping them the other way, but. . .. this is the way I chose to do it.  

 

                So this is what these three players did in their fourth seasons, and in several seasons following that:

 

First

Last

YEAR

G

AB

R

H

2B

3B

HR

RBI

BB

SO

SB

CS

Avg

OBA

SPct

OPS

Wayne

Causey

1961

104

312

37

86

14

1

8

49

37

28

0

0

.276

.348

.404

.752

Ed

Kranepool

1966

146

464

51

118

15

2

16

57

41

66

1

1

.254

.316

.399

.715

Robin

Yount

1977

154

605

66

174

34

4

4

49

41

80

16

7

.288

.333

.377

.710

                                     

AVERAGE

Year 4

1968

135

460

51

126

21

2

9

52

40

58

6

3

.274

.329

.390

.720

                                     

Wayne

Causey

1962

117

305

40

77

14

1

4

38

41

30

2

0

.252

.340

.344

.684

Ed

Kranepool

1967

141

469

37

126

17

1

10

54

37

51

0

4

.269

.321

.373

.694

Robin

Yount

1978

127

502

66

147

23

9

9

71

24

43

16

5

.293

.323

.428

.752

                                     

AVERAGE

Year 5

1969

128

425

48

117

18

4

8

54

34

41

6

3

.274

.325

.388

.713

                                     

Wayne

Causey

1963

139

554

72

155

32

4

8

44

56

54

4

2

.280

.345

.395

.740

Ed

Kranepool

1968

127

373

29

86

13

1

3

20

19

39

0

3

.231

.271

.295

.566

Robin

Yount

1979

149

577

72

154

26

5

8

51

35

52

11

8

.267

.308

.371

.679

                                     

AVERAGE

Year 6

1970

138

501

58

132

24

3

6

38

37

48

5

4

.263

.309

.361

.670

                                     

Wayne

Causey

1964

157

604

82

170

31

4

8

49

88

65

0

1

.281

.377

.386

.763

Ed

Kranepool

1969

112

353

36

84

9

2

11

49

37

32

3

2

.238

.307

.368

.675

Robin

Yount

1980

143

611

121

179

49

10

23

87

26

67

20

5

.293

.321

.519

.840

                                     

AVERAGE

Year 7

1971

137

523

80

144

30

5

14

62

50

55

8

3

.276

.341

.434

.774

 

 

                In Year 7 these three players averaged .276 with 14 homers, 62 RBI, 80 runs scored and a .774 OPS—a long step forward from what they had done at age 18:

 

First

Last

YEAR

G

AB

R

H

2B

3B

HR

RBI

BB

SO

SB

CS

Avg

OBA

SPct

OPS

AVERAGE

Year 1

1964

87

264

28

59

9

3

2

16

16

40

4

3

.223

.266

.302

.568

AVERAGE

Year 7

1971

137

523

80

144

30

5

14

62

50

55

8

3

.276

.341

.434

.774

 

                Of course, a cadre of three players doesn’t really mean anything; I’m just using this small group to illustrate the process.     These three, driven by Yount, actually continued to improve their OPS past the 7th season, although their playing time began to decline:

 

First

Last

YEAR

G

AB

R

H

2B

3B

HR

RBI

BB

SO

SB

CS

Avg

OBA

SPct

OPS

Wayne

Causey

1965

144

513

48

134

17

8

3

34

61

48

1

3

.261

.341

.343

.684

Ed

Kranepool

1970

43

47

2

8

0

0

0

3

5

2

0

0

.170

.250

.170

.420

Robin

Yount

1981

96

377

50

103

15

5

10

49

22

37

4

1

.273

.312

.419

.731

                                     

AVERAGE

Year 8

1972

94

312

33

82

11

4

4

29

29

29

2

1

.261

.323

.365

.688

                                     

Wayne

Causey

1966

106

243

24

58

8

2

0

18

31

19

3

0

.239

.318

.288

.606

Ed

Kranepool

1971

122

421

61

118

20

4

14

58

38

33

0

4

.280

.340

.447

.786

Robin

Yount

1982

156

635

129

210

46

12

29

114

54

63

14

3

.331

.379

.578

.957

                                     

AVERAGE

Year 9

1973

128

433

71

129

25

6

14

63

41

38

6

2

.297

.356

.481

.837

                                     

Wayne

Causey

1967

124

292

21

66

10

3

1

28

32

35

2

5

.226

.302

.291

.593

Ed

Kranepool

1972

122

327

28

88

15

1

8

34

34

35

1

0

.269

.336

.394

.731

Robin

Yount

1983

149

578

102

178

42

10

17

80

72

58

12

5

.308

.383

.503

.886

                                     

AVERAGE

Year 10

1974

132

399

50

111

22

5

9

47

46

43

5

3

.277

.352

.422

.774

                                     

Wayne

Causey

1968

79

148

10

22

2

1

1

11

14

12

0

0

.149

.223

.196

.419

Ed

Kranepool

1973

100

284

28

68

12

2

1

35

30

28

1

0

.239

.310

.306

.616

Robin

Yount

1984

160

624

105

186

27

7

16

80

67

67

14

4

.298

.362

.441

.803

                                     

AVERAGE

Year 11

1975

113

352

48

92

14

3

6

42

37

36

5

1

.261

.331

.370

.701

 

                After year 11 Wayne Causey dropped out of the majors.    After this, then, we are comparing apples with fewer apples.    After that it is no longer a comparison of a consistent group of players:

 

First

Last

YEAR

G

AB

R

H

2B

3B

HR

RBI

BB

SO

SB

CS

Avg

OBA

SPct

OPS

Ed

Kranepool

1974

94

217

20

65

11

1

4

24

18

14

1

0

.300

.350

.415

.765

Robin

Yount

1985

122

466

76

129

26

3

15

68

49

56

10

4

.277

.342

.442

.784

                                     

AVERAGE

Year 12

1980

108

342

48

97

19

2

10

46

34

35

6

2

.284

.349

.433

.783

                                     

Ed

Kranepool

1975

106

325

42

105

16

0

4

43

27

21

1

1

.323

.370

.409

.779

Robin

Yount

1986

140

522

82

163

31

7

9

46

62

73

14

5

.312

.388

.450

.838

                                     

AVERAGE

Year 13

1981

123

424

62

134

24

4

7

45

45

47

8

3

.316

.382

.434

.816

                                     

Ed

Kranepool

1976

123

415

47

121

17

1

10

49

35

38

1

0

.292

.344

.410

.754

Robin

Yount

1987

158

635

99

198

25

9

21

103

76

94

19

9

.312

.384

.479

.862

                                     

AVERAGE

Year 14

1982

141

525

73

160

21

5

16

76

56

66

10

5

.304

.368

.451

.820

                                     

Ed

Kranepool

1977

108

281

28

79

17

0

10

40

23

20

1

4

.281

.330

.448

.778

Robin

Yount

1988

162

621

92

190

38

11

13

91

63

63

22

4

.306

.369

.465

.834

                                     

AVERAGE

Year 15

1983

135

451

60

135

28

6

12

66

43

42

12

4

.298

.361

.460

.821

                                     

Ed

Kranepool

1978

66

81

7

17

2

0

3

19

8

12

0

0

.210

.280

.346

.625

Robin

Yount

1989

160

614

101

195

38

9

21

103

63

71

19

3

.318

.384

.511

.896

                                     

AVERAGE

Year 16

1984

113

348

54

106

20

5

12

61

36

42

10

2

.305

.374

.492

.866

                                     

Ed

Kranepool

1979

82

155

7

36

5

0

2

17

13

18

0

1

.232

.287

.303

.591

Robin

Yount

1990

158

587

98

145

17

5

17

77

78

89

15

8

.247

.337

.380

.717

                                     

AVERAGE

Year 17

1985

120

371

53

91

11

3

10

47

46

54

8

5

.244

.331

.364

.694

 

                The Group Average OPS goes all the way up to .866 in the 16th season, but of course there is no valid comparison to the earlier averages, because the "group" is not the same as it was, and 80% of the playing time in the Year-16 group is accounted for by Robin Yount.     After Year 17 Yount is all that is left of this group of three players:

 

First

Last

YEAR

G

AB

R

H

2B

3B

HR

RBI

BB

SO

SB

CS

Avg

OBA

SPct

OPS

Robin

Yount

1991

130

503

66

131

20

4

10

77

54

79

6

4

.260

.332

.376

.707

                                     

AVERAGE

Year 18

1991

130

503

66

131

20

4

10

77

54

79

6

4

.260

.332

.376

.707

                                     
                                     

Robin

Yount

1992

150

557

71

147

40

3

8

77

53

81

15

6

.264

.325

.390

.714

                                     

AVERAGE

Year 19

1992

150

557

71

147

40

3

8

77

53

81

15

6

.264

.325

.390

.714

                                     
                                     

Robin

Yount

1993

127

454

62

117

25

3

8

51

44

93

9

2

.258

.326

.379

.705

                                     

AVERAGE

Year 20

1993

127

454

62

117

25

3

8

51

44

93

9

2

.258

.326

.379

.705

 

                OK; that’s just to explain the process of the research, make sure you understand the flaws and limitations of the method.     Now we can get to the real research.   

 

                First, let’s look at the number of players who are rookies at each age:

 

Number of Players

Rookie Age

3

18

11

19

48

20

111

21

172

22

202

23

212

24

135

25

67

26

26

27

12

28

5

29

2

30

 

                The peak age for rookiedom, in this study, is age 24.    This study would skew slightly younger than all rookies, because we are only studying players who had careers of 800 games or more.   If we included players who had shorter careers, more of them would have had their rookie seasons at ages 25 and up.   But among players who go on to good careers, the peak rookie ages are 23 and 24.  

 

                As to the quality of the rookies, the highest quality is for the youngest players.     Among 19-year-old rookies, there are only 11 players in the group, but three of those are in the Hall of Fame (Mickey Mantle, Bill Mazeroski and Al Kaline), and a fourth will be (Ken Griffey, Jr.)    A fifth, Tony Congiliaro, would be in the Hall of Fame if he hadn’t gotten hurt and/or sick, and two others, Rusty Staub and Cesar Cedeno, had careers of near-Hall of Fame stature.    Alex Rodriguez was a rookie at age 19, but he’s not in this data because he is still active.   Players who play regularly at a very early age are generally exceptional players.     This chart counts the number of Hall of Famers, by their ages as rookies:

 

Number of Players

Rookie Age

Hall of Famers

Percentage

3

18

1

33%

11

19

3

27%

48

20

12

25%

111

21

10

9%

172

22

7

4%

202

23

8

4%

212

24

2

1%

135

25

0

0%

67

26

0

0%

26

27

0

0%

12

28

0

0%

5

29

0

0%

2

30

0

0%

 

                One-third of players who are rookies at ages 18 through 20 either are in the Hall of Fame or will be one day.     That percentage drops sharply after age 20.  

 

                Turning our attention now to the question posed by the reader, which is the rate of improvement which may be anticipated from a group of rookies.  . . .this chart summarizes the material given earlier, for the 18-year-old rookies:

 

PLAYERS WHO ARE ROOKIES AT AGE 18

#

Yr

G

AB

R

H

2B

3B

HR

RBI

BB

SO

SB

CS

Avg

OBA

SPct

OPS

3

1

87

264

28

59

9

3

2

16

16

40

4

3

.223

.266

.302

.568

3

2

106

355

40

91

16

2

6

34

24

47

4