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New Pitcher Projection Method

Frankly, I never wanted to do pitcher projections, but I didn't feel I could avoid it if I did the hitter projections from NPB to MLB. I'd never seen pitcher projections done, and I'm still unfamiliar with the workings of the other efforts out there to do such projections of pitchers. I thought I could get away with simply using the inverse of the factors for hitters, and so I tried that. The truth is, it didn't work too well.

I didn't have much of a clue on how to fix the pitching projections for quite some time. The first breakthrough I had was the realization that projecting runs based upon the runs (allowed, scored, or batted in) in one place to the other league when the leagues have such differing effects on the pieces which make up those runs just doesn't work. What I'm trying to say is that average is much less effected by the difference of the leagues than homers are. As a result, an Ichiro will retain much more of his value in the majors from NPB than a power hitter like Hideki Matsui will. If you try to use one run factor for both Hideki Matsui and Ichiro, that truth is lost in the run and RBI projections. If you project the run and RBI figures from how many runs each man projects to produce under a runs created formula, Hideki Matsui's RBI and runs scored will be reduced more than Ichiro's will, as will occur in real life. The same is true for pitchers.

The means for calculating pitching runs came from Bill James' component ERA. I tried to use component ERA on the existing conversions of hits, homers, walks, and homers, and it was quite clear that my conversion factors worked poorly, especially the ones for walks and strikeouts. A major problem, beyond even the fact these particular statistics do not seem to project quite as well as many of the others, was that the factors were based on the hitters that played in both leagues. This subset of hitters had a lot of slow power hitters, and few singles hitters. This created major distortions in the conversion factors.

At that point, the only thing to do was to do a comparison of the performance of pitchers who pitched in both the majors and NPB. I used matched numbers of innings pitched (with a minimum of 0.1 IP) for the pitchers in both settings. What I got from 169 pitchers were 14907.2 matched innings, each pitcher pitching the same number of innings in each league. The results were as follows:
League hits   homers   walks   strikeouts
Japan 14624 1545 5832 10963
Majors 15737 1910 6252 9695
================== ===== ==== ==== =====
Adjustment factors*   1.076 1.236 1.072 0.884

* = Japan to majors
From the runs, I calculated a won-loss percentage using Bill James Pythagorean Theorem, and gave each starter one decision for each 9 innings pitched. As before, for pitchers from 1990 on, I allowed their innings pitched to rise in the projection, as innings pitched in Japan had dropped to levels similar to what one would expect in the majors in seasons as short as those played in Japan. Reliever won/lost totals were left alone, as the way the pitcher is used has such a dramatic effect on won-lost records for relievers that I thought it best not to mess with it. Saves were reduced if a pitcher's ERA rose over 3.00 by a very crude approach. Now I had all the means to try my new adjustment method, and I think it performs much better.

Now, it is time to show you how this method performs so you can decide for yourself. I'll do projections from the last five seasons of the main pitchers imported from Japan in the 1990's (so long as they played at least that many), then put a break, then show their first five seasons in the majors (again, so long as they played that many). After that, I'll make some comment on how I think the projection performed for that pitcher.

Kazuhisa Ishii
Year   League Games   Won   Lost   Saves   Innings   Hits   HR    BB    K    Runs    ER    ERA
1997 Japan   20 9 5 0 129.2 93 7 63 125 52 44 3.05
1998 Japan   31 9 11 0 215.1 192 18 135 256 129 116 4.85
1999 Japan   25 5 9 0 144.0 159 24 91 172 120 111 6.94
2000 Japan   32 10 9 0 200.2 176 22 93 221 108 95 4.26
2001 Japan   29 8 10 0 189.2 168 26 102 177 112 100 4.75
==== ========   == == == == ===== === === === === === === =====
2002 Majors   28 14 10 0 154.0 137 20 106 143 82 73 4.27
2003 Majors   27 9 7 0 147.0 129 16 101 140 72 63 3.86
2004 Majors   31 13 8 0 172.0 155 21 98 99 97 90 4.71

I'd say his projection is quite reasonable. My previous attempt at projecting his record can be found here

Shingo Takatsu
Year   League Games   Won   Lost   Saves   Innings   Hits   HR    BB    K    Runs    ER    ERA
1999 Japan   46 1 1 17 48.0 41 9 10 40 23 20 3.75
2000 Japan   37 0 1 0 37.0 41 6 10 31 24 22 5.35
2001 Japan   50 0 4 14 55.1 61 4 16 40 31 28 4.55
2002 Japan   50 0 2 9 47.0 46 9 14 29 27 24 4.60
2003 Japan   46 2 3 0 43.2 52 10 26 27 41 38 7.83
==== ========   == == == == ===== === === === === === === =====
2004 Majors   59 6 4 19 62.1 40 6 21 50 17 16 2.31

At least in 2004, he dramatically outpitched his projection. It will be interesting to see if he can keep it up. My previous attempt at projecting his record can be found here

Shigetoshi Hasegawa
Year   League Games   Won   Lost   Saves   Innings   Hits   HR    BB    K    Runs    ER    ERA
1992 Japan   26 4 10 0 154.0 185 18 68 95 120 111 6.49
1993 Japan   25 7 11 0 176.2 196 18 64 95 116 105 5.35
1994 Japan   22 8 7 0 138.1 161 13 44 67 72 64 4.16
1995 Japan   24 8 11 0 173.0 199 22 61 89 113 102 5.31
1996 Japan   19 2 8 0 91.1 146 18 53 61 115 110 10.84
==== ========   == == == == ===== === === === === === === =====
1997 Majors   50 3 7 0 116.2 118 14 46 83 60 51 3.93
1998 Majors   61 8 3 5 97.1 86 14 32 73 37 34 3.14
1999 Majors   64 4 6 2 77.0 80 14 34 44 45 42 4.91
2000 Majors   66 10 6 9 95.2 100 11 38 59 43 38 3.57
2001 Majors   46 5 6 0 55.2 52 5 20 41 28 25 4.04

It's a little hard to make the comparisons for him as he was used as a starter in Japan, and as a reliever in the majors. He pitched better than the projection, but I've got to wonder how much of the improvement was due to the change in role.

Masato Yoshii
Year   League Games   Won   Lost   Saves   Innings   Hits   HR    BB    K    Runs    ER    ERA
1993 Japan   24 4 8 0 113.0 134 11 33 73 76 69 5.50
1994 Japan   19 4 6 0 85.2 112 17 35 33 63 57 5.99
1995 Japan   26 9 8 0 153.2 151 19 46 89 80 70 4.10
1996 Japan   27 6 11 0 198.1 237 31 63 160 148 136 6.17
1997 Japan   30 9 10 0 189.1 190 22 61 109 105 93 4.42
==== ========   == == == == ===== === === === === === === =====
1998 Majors   29 6 8 0 171.2 166 22 53 117 79 75 3.93
1999 Majors   31 12 8 0 174.0 168 25 58 105 86 85 4.40
2000 Majors   19 6 15 0 167.1 201 32 53 88 112 109 5.86
2001 Majors   42 4 7 0 113.0 127 18 26 63 65 60 4.78
2002 Majors   31 4 9 0 131.1 143 15 32 74 66 60 4.11

I'd say he pitched a bit better than his projection.

Kazuhiro Sasaki
Year   League Games   Won   Lost   Saves   Innings   Hits   HR    BB    K    Runs    ER    ERA
1995 Japan   50 7 2 33 60.1 36 7 20 76 18 14 2.09
1996 Japan   45 4 3 4 57.0 50 9 21 88 32 28 4.42
1997 Japan   57 3 0 44 70.0 32 9 22 105 17 13 1.67
1998 Japan   59 1 1 52 65.1 41 1 17 82 16 12 1.65
1999 Japan   26 1 1 6 26.1 25 1 8 36 12 10 3.42
==== ========   == == == == ===== === === === === === === =====
2000 Majors   63 2 5 37 62.2 42 10 31 78 25 22 3.16
2001 Majors   69 0 4 45 66.2 48 6 11 62 24 24 3.24
2002 Majors   61 4 5 37 60.2 44 6 20 73 24 17 2.52
2003 Majors   35 1 2 10 33.1 31 2 15 29 17 15 4.05

He wasn't quite as good as he was in the projected seasons, but he was quite valuable his first three years in the majors. My previous attempt at projecting his record can be found here

Hideo Nomo
Year   League Games   Won   Lost   Saves   Innings   Hits   HR    BB    K    Runs    ER    ERA
1990 Japan   33 11 15 0 267.1 224 28 146 316 149 133 4.48
1991 Japan   34 10 18 0 268.1 245 32 171 316 180 164 5.50
1992 Japan   33 10 16 0 239.2 201 20 156 251 141 127 4.77
1993 Japan   35 9 20 0 263.2 270 34 198 304 214 198 6.76
1994 Japan   15 6 6 0 101.0 91 10 82 99 57 51 4.54
==== ========   == == == == ===== === === === === === === =====
1995 Majors   28 13 6 0 191.1 124 5 78 236 63 54 2.54
1996 Majors   33 16 11 0 228.1 180 2 85 234 93 81 3.19
1997 Majors   33 14 12 0 207.1 193 9 92 233 104 98 4.25
1998 Majors   29 6 12 0 157.1 130 4 94 167 88 86 4.92
1999 Majors   28 12 8 0 176.1 173 3 78 161 96 89 4.54

He was better than the projection in the first two years, though the fact he wasn't used as hard may explain it. After that, he was rather similar to the projections. My previous attempt at projecting his record can be found here

Hideki Irabu
Year   League Games   Won   Lost   Saves   Innings   Hits   HR    BB    K    Runs    ER    ERA
1992 Japan   29 0 5 0 80.1 105 3 49 61 68 63 7.06
1993 Japan   34 5 10 0 153.1 168 17 77 176 111 101 5.93
1994 Japan   24 13 7 0 183.1 162 17 89 187 78 66 3.24
1995 Japan   31 14 8 0 221.1 186 12 85 234 91 78 3.17
1996 Japan   27 11 7 0 183.1 145 11 70 184 80 69 3.39
==== ========   == == == == ===== === === === === === === =====
1997 Majors   13 5 4 0 53.1 69 15 20 56 47 42 7.09
1998 Majors   29 13 9 0 173.0 148 27 76 126 78 78 4.06
1999 Majors   32 11 7 0 169.1 180 26 46 133 98 91 4.84
2000 Majors   11 2 5 0 54.2 77 9 14 42 45 44 7.24
2001 Majors   3 0 2 0 16.2 22 3 3 18 9 9 4.86

He didn't pitch as badly as his press from his stay in the majors would indicate. However, according to the projections, he seriously underachieved. I'd say the projection captures an essential fact about Irabu: he had that kind of talent, but his emotional makeup was such that going to a high pressure situation with the Yankees on top of the culture shock was more than he could handle. Therefore, he underachieved. My previous attempt at projecting his record can be found here

Akinori Otsuka
Year   League Games   Won   Lost   Saves   Innings   Hits   HR    BB    K    Runs    ER    ERA
1999 Japan   29 1 4 0 34.2 31 1 13 34 16 14 3.63
2000 Japan   43 1 3 10 46.1 40 4 17 52 22 19 3.69
2001 Japan   55 2 5 15 64.1 52 10 19 84 29 25 3.50
2002 Japan   47 2 1 25 49.0 27 6 4 55 9 6 1.10
2003 Japan   58 1 3 15 49.0 39 6 6 57 16 13 2.39
==== ========   == == == == ===== === === === === === === =====
2004 Majors   73 7 2 2 77.1 56 6 26 87 16 15 1.75

I'd say the projection did well in his case. My previous attempt at projecting his record can be found here

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