In baseball discussions everywhere, you’ll hear pitchers described in terms of their rotation slots. “He’s a #1 starting pitcher.”, or “He’s no better than a #4 or #5 starting pitcher.” Ever sit back and think, “What exactly is it that qualifies a pitcher as a #1,#2,#3,#4, or #5 starting pitcher?” Well, I’ve attempted to statistically define the starting pitcher rotation slots.

My method for defining the rotation slots is as follows: I first extracted all starting pitching data only. I then sorted the data for all pitchers in each league by ERA (Then later XERA). Then, for each league, beginning at the top of the list, I totalled up enough IP to account for a #1 SP for each team in the league. I totalled the statistics for these pitchers and divided by the number of teams in the league to come up with the average #1 SP for the league. I then repeated this process with the remaining pitchers for each of the remaining pitching rotation slots #2 – #5. I determined the number of innings pitched for each rotation slot, by trying to come as close to the following as I could.

Slot IP
#1 220
#2 210
#3 200
#4 190
#5 The Rest

This is the second year for which I have ran these numbers. The numbers from the 2004 data are below for reference:

2004 ERA Rotation Slots

AL SP Rot Slots W L ERA GS IP H ER HR BB SO WHIP XERA
Avg AL #1 SPL 14 9 3.60 34 218 204 87 22 59 172 1.21 3.55
Avg AL #2 SPL 14 11 4.38 34 208 218 101 24 67 135 1.37 4.37
Avg AL #3 SP 12 12 4.89 34 199 213 108 28 73 123 1.44 4.81
Avg AL #4 SP 10 12 5.32 33 190 215 112 29 71 122 1.51 5.25
Avg AL #5 SP 5 13 6.78 28 140 177 105 27 60 82 1.70 6.46
Avg AL SP 11 11 4.84 32 191 205 102 26 66 126 1.42 4.75

Rot Slots ERA Range
AL #1 SP = 5.59

NL SP Rot Slots W L ERA GS IP H ER HR BB SO WHIP XERA
Avg NL #1 SP 15 10 3.05 34 221 190 75 20 69 196 1.17 3.14
Avg NL #2 SP 12 12 3.80 34 212 207 90 23 71 157 1.31 3.96
Avg NL #3 SP 12 10 4.33 34 201 210 97 24 72 127 1.40 4.48
Avg NL #4 SP 11 12 5.03 34 188 208 105 29 69 121 1.47 5.11
Avg NL #5 SP 5 12 7.27 25 120 152 97 24 59 75 1.76 6.66
Avg NL SP 11 11 4.43 32 189 194 93 24 68 135 1.39 4.45

Rot Slots ERA Range
NL #1 SP = 5.52

2004 XERA Rotation Slots

AL SP Rot Slots W L ERA GS IP H ER HR BB SO WHIP XERA
Avg AL #1 SP 14 9 3.64 34 215 197 87 21 63 173 1.21 3.46
Avg AL #2 SP 14 12 4.47 35 213 217 106 26 73 145 1.36 4.33
Avg AL #3 SP 12 12 4.96 33 196 213 108 27 67 123 1.42 4.82
Avg AL #4 SP 10 11 5.20 33 190 218 110 28 68 114 1.51 5.27
Avg AL #5 SP 5 13 6.60 28 141 183 103 27 59 79 1.72 6.59
Avg AL SP 11 11 4.84 32 191 205 102 26 66 126 1.42 4.75

Rot Slots XERA Range
AL #1 SP = 5.56

NL SP Rot Slots W L ERA GS IP H ER HR BB SO WHIP XERA
Avg NL #1 SP 15 9 3.13 35 220 187 77 18 70 204 1.17 3.05
Avg NL #2 SP 12 12 3.82 34 213 207 90 23 69 152 1.30 3.92
Avg NL #3 SP 12 10 4.44 33 195 202 96 25 70 131 1.39 4.51
Avg NL #4 SP 10 11 4.91 34 187 207 102 28 70 111 1.48 5.09
Avg NL #5 SP 6 13 6.79 28 138 176 104 28 64 86 1.74 6.62
Avg NL SP 11 11 4.43 32 189 194 93 24 68 135 1.39 4.45

Rot Slots XERA Range
NL #1 SP = 5.69

The following is the data for the 2005 season:

ERA Rot Slots

AL SP Rot Slots W L ERA GS IP H R ER HR BB SO WHIP XERA
Avg AL #1 SP 15 9 3.22 33 216 201 85 77 20 56 147 1.19 3.44
Avg AL #2 SP 14 11 3.86 34 218 215 103 93 25 60 148 1.26 3.95
Avg AL #3 SP 13 12 4.40 35 213 223 113 104 25 62 134 1.34 4.31
Avg AL #4 SP 11 14 5.22 35 201 226 124 116 28 73 117 1.49 5.08
Avg AL #5 SP 6 12 6.68 26 133 169 106 99 21 52 79 1.66 6.04
Avg AL SP 12 11 4.50 32 195 205 105 97 24 60 124 1.36 4.43

Rot Slots ERA Range
AL #1 SP = 5.79

NL SP Rot Slots W L ERA GS IP H R ER HR BB SO WHIP XERA
Avg NL #1 SP 15 8 2.84 33 218 186 76 69 17 61 180 1.13 2.94
Avg NL #2 SP 13 11 3.74 33 211 212 95 88 23 66 154 1.32 4.08
Avg NL #3 SP 12 12 4.27 34 203 210 104 96 26 62 134 1.34 4.36
Avg NL #4 SP 10 14 4.79 34 192 205 110 102 25 71 122 1.44 4.75
Avg NL #5 SP 7 12 6.31 27 142 171 106 100 24 65 87 1.66 5.98
Avg NL SP 11 12 4.23 32 195 198 99 91 23 66 136 1.36 4.28

Rot Slots ERA Range
NL #1 SP = 5.10

XERA Rot Slots

AL SP Rot Slots W L ERA GS IP H R ER HR BB SO WHIP XERA
Avg AL #1 SP 16 10 3.39 35 230 206 94 87 23 64 172 1.17 3.33
Avg AL #2 SP 14 10 4.06 35 212 212 104 96 22 66 141 1.31 3.96
Avg AL #3 SP 11 12 4.26 32 195 207 102 92 25 49 115 1.31 4.39
Avg AL #4 SP 11 12 5.04 32 185 205 110 104 23 67 109 1.47 4.91
Avg AL #5 SP 7 14 6.39 30 157 202 120 111 26 57 89 1.66 6.17
Avg SL SP 12 11 4.50 32 195 205 105 97 24 60 124 1.36 4.43

Rot Slots XERA Range
AL #1 SP = 5.16

NL SP Rot Slots W L ERA GS IP H R ER HR BB SO WHIP XERA
Avg NL #1 SP 15 8 2.91 33 217 183 77 70 17 61 186 1.12 2.89
Avg NL #2 SP 12 11 3.87 33 208 207 96 90 23 62 150 1.29 3.96
Avg NL #3 SP 12 12 4.23 33 201 211 103 94 23 61 128 1.36 4.36
Avg NL #4 SP 11 14 4.72 34 191 202 108 100 26 77 121 1.46 4.81
Avg NL #5 SP 7 13 6.08 28 149 182 107 100 26 63 91 1.65 6.07
Avg NL SP 11 12 4.23 32 195 198 99 91 23 66 136 1.36 4.28

Rot Slots XERA Range
NL #1 SP = 5.25

So how do the Reds SPs stack up? Listed below are all SPs for the Reds in 2005, plus newly acquired Dave Williams. They are ranked first by ERA, then by XERA.

Reds SP ERA

NL #2 SP W L ERA GS IP H R ER HR BB SO WHIP XERA
AHarang 11 13 3.83 32 211.6 217 93 90 22 51 163 1.27 3.95

NL #3 SP W L ERA GS IP H R ER HR BB SO WHIP XERA
BClaussen 10 11 4.21 29 166.6 178 89 78 24 57 121 1.41 4.77
DWilliams 10 11 4.41 25 138.6 137 74 68 20 58 88 1.41 4.56

NL #5 SP W L ERA GS IP H R ER HR BB SO WHIP XERA
MBelisle 2 2 5.25 5 24.0 29 15 14 6 6 17 1.46 6.16
RaOrtiz 9 11 5.36 30 171.3 206 110 102 34 51 96 1.50 5.83
RKeisler 0 1 5.40 4 18.3 25 16 11 4 13 15 2.08 7.87
EMilton 8 15 6.47 34 186.3 237 141 134 40 52 123 1.55 6.27
LHudson 6 8 7.20 16 75.0 78 60 60 14 47 47 1.67 5.71
PWilson 1 5 7.77 9 46.3 68 41 40 10 17 30 1.84 7.52
ERamirez 0 3 9.31 4 19.3 30 20 20 5 7 8 1.92 8.34

Reds SP XERA

NL #2 SP W L ERA GS IP H R ER HR BB SO WHIP XERA
AHarang 11 13 3.83 32 211.6 217 93 90 22 51 163 1.27 3.95

NL #4 SP W L ERA GS IP H R ER HR BB SO WHIP XERA
DWilliams 10 11 4.41 25 138.6 137 74 68 20 58 88 1.41 4.56
BClaussen 10 11 4.21 29 166.6 178 89 78 24 57 121 1.41 4.77

NL #5 SP W L ERA GS IP H R ER HR BB SO WHIP XERA
LHudson 6 8 7.20 16 75.0 78 60 60 14 47 47 1.67 5.71
RaOrtiz 9 11 5.36 30 171.3 206 110 102 34 51 96 1.50 5.83
MBelisle 2 2 5.25 5 24.0 29 15 14 6 6 17 1.46 6.16
EMilton 8 15 6.47 34 186.3 237 141 134 40 52 123 1.55 6.27
PWilson 1 5 7.77 9 46.3 68 41 40 10 17 30 1.84 7.52
RKeisler 0 1 5.40 4 18.3 25 16 11 4 13 15 2.08 7.87
ERamirez 0 3 9.31 4 19.3 30 20 20 5 7 8 1.92 8.34

I have found this data to be very enlightening. Please feel free to use the ERA ranges above as a reference the next time you see a pitcher referred to in terms if their rotation slot. I’ve found that most people who discuss pitchers in the terms of rotation slots, really don’t have a solid frame of reference to assign pitchers to their proper slots.

Later,
Tom

Join the conversation! 2 Comments

  1. Tom, great article. Anyone know how projections for Harang, Claussen, and Williams look for ’06? I’d like to see them give Belisle a shot at the rotation, and the small sample size from last year makes his numbers appear worse than they would if you looked at individual appearances.

  2. Redleg Nation: Starting Pitcher Rotation Slots Defined

    Redleg Nation has done the grunt work in assessing just how good a No. 1 or 2 or 3 starter is, based on innings pitched.

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2005 Reds, Baseball - General, Reds - General