Developmental Player System
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The Developmental Player System(育成選手制度, Ikusei Sensyu Seido) is a system that allows players to be held for the purpose of training players separately from the 70 registered players under control of each team created in the fall of 2005 at Nippon Professional Baseball (NPB). It is akin to the practice squads seen in other sports.
Summary
The system was established in 2005 to create an environment in which amateur players could gain playing experience after company-owned amateur baseball teams were folding following the economic recession of the Lost Decades. Players who are part of the system are considered "semi-controlled" in that they play for the team they are signed to but they are not a controlled player and thus their team doe not have exclusive rights to them.
The Developmental Player System include players drafted as rookies (e.g. Yusuke Kosai, Michitaka Nishiyama), foreign players signed as developmental players (e.g., Raidel Martínez, Liván Moinelo), players drafted as registered players under control but re-signed with a team as developmental players due to their abilities (e.g., Kenta Kurose), players who became free agents with their former team and signed with another team (e.g., Masaru Nakamura, Kouya Fujii), and players who were removed from the registration of players under control and re-signed as a developmental player as an injury rehabilitation assignment (e.g., Takuya Kuwahara, Hiroya Shimamoto). There is an argument that de-registering players who cannot play due to injury and re-signing them as developmental players will protect their careers; on the other hand, the use of the developmental players system, instead of systems like the Major League Baseball (MLB) Injured list, is criticized as contrary to the original intent of this system to develop and provide opportunities to amateur players. The oldest player to become a developmental player is Soichi Fujita, who signed in 2011 at the age of 39. The longest period as a developmental player was Kousuke Naruse[jp]'s eight seasons (2011-2018) as of the 2022 season.
Regulations for Developmental Players

Player Rules
- Developmental players are not allowed to participate in official NPB games. However, up to five players per team per game are allowed to play in the Eastern League and Western League, the NPB's minor leagues. These minor league farm teams are considered a team's second squad. If a team as a large amount of developmental and minor league players, they may form a third squad and play in games against independent league teams (such as the Shikoku Island League Plus and Baseball Challenge League), corporate amateur teams, or university teams. The Fukuoka SoftBank Hawks's third squad plays more than 100 games a year. While there is a difference in contract between a registered players under control and a developmental players, unlike the relationship between players Major League Baseball and Minor League Baseball in North America, all NPB are players on the same team regardless of which squad they are on, and use the same practice facility and player dormitory.
- A Developmental Player System contract is for a maximum of three years. After this contract expires, the player can become a free agent once and sign with the same team again for a one year extension. After the fourth season, and each subsequent season, the NPB will announce the player's free agent status. This measure is intended to increase the player's chances of signing a registration of players under control contract, and during the free agent period, he can negotiate with other teams. For example, in 2019, Hiroki Hasegawa moved from the Fukuoka Softbank Hawks to the Tokyo Yakult Swallows. A one-year contract is also possible for a registered players under control to re-sign as a developmental player after a free agent announcement has been made. Players who have not been under contract for three seasons will be placed on the roster of pending developmental players, and other teams will not be able to negotiate with them.
- The minimum salary is ¥2.4 million and ¥3 million is paid as a preparation fee when drafted. However, since there is no cap on annual salary, some teams sign players at higher salaries, and players who are re-signed as developmental players from a registered players under control often maintain the salary level of a registered players under control.
- A developmental player's uniform number will be a three-digit number (e.g. 001, 101, or 201) in the numbers of other players and staff being one- or two-digits.
Regulations for teams that own developmental players
- The deadline for re-signing a developmental player to a registered player under control contract is from the end of the season to July 31st during the following season. However, teams are not permitted to change a player's contract status from a registered under control to developmental during the season.
- Developmental players can only be owned by teams with at least 65 controlled players on their roster by July 31 each eason, and teams with fewer than 65 controlled players cannot own them. However, if a team reports to the Executive Committee that it has re-signed a developmental player as a controlled player or acquired a new controlled player to bring the number of controlled players to 65 or more, and if this is approved, the team may retain the developmental player. There is no limit to the number of developmental players owned and how many a team has depends on the team's policy. For example, the Yomiuri Giants and Fukuoka SoftBank Hawks often have more than 30 developmental players, enough to field a third-level squad; conversely, the Hanshin Tigers tend to have only a few players. The Fukuoka SoftBank Hawks selected 14 new developmental players in the 2022 draft to implement a four-team system starting in the 2023 season.
Developmental Players Draft Meeting
- If the total number of players selected at the end of the Rookie Player Selection Conference has not reached 120, a Developmental Players Selection Meeting will be held with the participation of the teams that wish to participate.
Developmental players trade
- Article 11 of the Nippon Professional Baseball Developed Player Regulations states that a trade of a developmental player held by July 31 is allowed, but as of the 2022 season, there are no examples of such a trade.
Outcome

The developmental player system, which began in the 2005 season, has been successful in producing major players for each team (e.g. Yoshiki Sunada, Yuji Nishino). The Yomiuri Giants, who have been heavily utilizing this system since the beginning, have signed more than 50 developmental players as their registered players under control as of the 2022 season. The Fukuoka Softbank Hawks have also signed 40 developmental players as their registered players under control, and have produced players like Kodai Senga and Takuya Kai who have won league titles and awards and represented Japanese baseball on the national baseball team. The Hokkaido Nippon-Ham Fighters, which had been reluctant to acquire developmental players, drafted a player as a developmental player for the first time in the 2018 draft. In the 2022 draft, 51 players will be selected as developmental players, the largest number in history, and the acquisition of developmental players is a growing trend.
| Player name | Team | enrollment | League Titles and Awards |
|---|---|---|---|
| Shuta Ishikawa | Fukuoka SoftBank Hawks | 2013 Draft. | 1× Pacific League winning percentage leader (2020) 1× Pacific League the most wins Champion (2020) Pitched a no-hitter on August 18, 2023 |
| Takuya Kai | Fukuoka SoftBank Hawks | 2010 Draft. | 6× Pacific League Golden Glove Award (2017–2022) 3× Pacific League Best Nine Award (2017, 2020. 2022) |
| Raidel Martínez | Chunichi Dragons | Signed in 2017. | 1× Central League Saves leader (2022) |
| Tetsuya Matsumoto | Yomiuri Giants | 2006 Draft. | 1× Central League Rookie of the Year (2009) |
| Liván Moinelo | Fukuoka SoftBank Hawks | Signed in 2017. | 1× Pacific League Best Relief Pitcher Award (2020) 1× Pacific League Holds leader (2020) |
| Yoshifumi Okada | Chiba Lotte Marines | 2008 Draft. | 2× Pacific League Golden Glove Award (2011, 2012) |
| Yariel Rodríguez | Chunichi Dragons | Signed in 2020. | 1× Central League Best Relief Pitcher Award (2022) 1× Central League Holds leader (2022) |
| Kodai Senga | Fukuoka SoftBank Hawks | 2010 Draft. | 2× Pacific League strikeout leader (2019, 2020) 1× Pacific League ERA leader (2020) 1× Pacific League winning percentage leader (2017) 1× Pacific League the most wins champion (2020) 2× Pacific League Best Nine Award (2019, 2020) 2× Pacific League Golden Glove Award (2019, 2020) Pitched a no-hitter on September 6, 2019 |
| Ukyo Shuto | Fukuoka SoftBank Hawks | 2017 Draft. | 1×Pacific League Stolen bases Leader (2020) |
| Tetsuya Yamaguchi | Yomiuri Giants | 2005 Draft. | 1× Central League Rookie of the Year (2009) 3× Central League Best Relief Pitcher Award (2009, 2012-2013) |
Current developmental player rosters
Central League
| Position | Players | source | |
|---|---|---|---|
| Chunichi Dragons | |||
| Pitchers | 201 Ryushin Takeuchi 202 Frank Álvarez 204 Tubasa Kato 205 Kenshin Kakigoshi 208 Sho Ishikawa | 210 Toshiya Okada 212 Tensho Nonaka 213 Akio Moriyama 214 Ren Kondoh 216 Towa Kikuta | |
| Catchers | 215 Toki Hiwatari | ||
| Infielders | 207 Mao Hoshino | 218 Rii Kawakami | |
| Outfielders | 211 Yuma Fukumoto | 220 Carlos Monier | |
| Hanshin Tigers | |||
| Pitchers | 122 Ippei Ogawa 123 Kai Matsubara 125 Ryo Itoh | 131 Jose Betances 132 Anthony Martinez | |
| Outfielders | 126 Kein Fukushima | ||
| Hiroshima Toyo Carp | |||
| Pitchers | 120 Takeru Sugita 122 Rei Sakata 125 Taiga Tsuji | 126 So Shinya 128 Mirai Sugihara 129 Raisei Nakamura | |
| Infielders | 127 Seita Maekawa | 130 Moises Ramírez | |
| Outfielders | 121 Norihiko Nabara | 131 Nelson Robert | |
| Tokyo Yakult Swallows | |||
| Pitchers | 012 Hiroki Kondo 013 Kota Katekaru 015 Shohei Numata | 016 Yusei Nishihama 017 Shosei 019 Shinnosuke Shimo | |
| Catchers | 025 Felipe Kisu | ||
| Infielders | 026 Sota Takano | ||
| Yokohama DeNA BayStars | |||
| Pitchers | 101 Haruto Kusano 102 Manato Shimizu 105 Wilny Moron 106 Aki Watanabe | 107 Hansel Marcelino 108 Ryuto Konno 110 Alexander Martínez 122 Haruto Shoji | |
| Catchers | 116 Ryuhei Kuki | 130 Taiga Kondoh | |
| Infielders | 100 Ren 125 So Ogasawara 133 Ryunosuke Aibara | 144 Daichi Kobukata 193 Ikumi Takamizawa | |
| Outfielders | 103 Nagi Murakawa | ||
| Yomiuri Giants | |||
| Pitchers | 011 Naoki Kasashima 012 Katsunari Miura 015 Haruto Kawasaki 016 Takahiro Chiba 018 Motoya Kinoshita 019 Junki Sonoda 020 Natsuki Toda 021 Kenta Onuma 023 Tomoki Tamura | 026 Yusefu Yoshimura 028 Ryu Tomida 030 Yusuke Yamasaki 034 Tessei Morimoto 035 Elvis Luciano 041 Huang Chin-hao 047 Eiji Kamouchi 063 Yuki Hanada | |
| Catchers | 006 Hayato Sakamoto 010 Ryoya Ohtsu 022 Keita Kameda | 024 Kenki Maeda 069 Tetsu Hagiwara | |
| Infielders | 001 Ren Kato 004 Gen Murayama 005 Yuya Tanoue 007 Kisara Utsunomiya | 008 Hakuto Aizawa 025 Hiroto Okamoto 027 Rio Kitamura | |
| Outfielders | 003 Yamato Suzuki 009 Misaki Sasahara 013 Julian Tima 031 Rui Mitsuka | 033 Kota Hirayama 037 Marek Chlup 044 Gen Ohshiro 051 Hidetora Funakoshi |
Pacific League
| Position | Players | source | |
|---|---|---|---|
| Chiba Lotte Marines | |||
| Pitchers | 120 Fuki Tanaka 121 Seiya Dohi 124 Takuro Furuya 125 Kirato Nagashimada | 127 Yuto Yoshikawa 128 Kaiki Shirahama 133 Ryota Takeuchi | |
| Catchers | 126 Ryosuke Murayama | 137 Konoshin Tomiyama | |
| Infielders | 129 Rui Katsumata 130 Kaisei Kurokawa | 134 Shinya Matsuishi | |
| Outfielders | 135 Hikaru Kohno 136 Kazuki Fujita | 138 Andy Martin | |
| Fukuoka SoftBank Hawks | |||
| Pitchers | 120 Hiroki Sato 125 Yuri Furukawa 126 Yuwa Miyasato 133 Kotaro Hoshino 134 Shinno Ohshiro 135 Alexander Armenta 136 Fuga Otake 139 Sanshiro Izaki 141 Mailon Felix 142 Haruto Fujiwara 143 Shun Murakami 145 Reiri Tanaka 146 Jumpei Fujita 147 Koki Kato 148 Takuma Yamasaki 152 Masaki Takimoto | 154 Takuma Sato 156 Luis Rodríguez 157 Jui Kobayashi 158 Ren Akaba 160 Keishin Nagamizu 161 Kaito Uchino 162 Junpei Okaue 163 Akito Sasaki 164 Sota Mizuguchi 165 Hayato Miyazaki 169 Yusei Tobita 172 Yuki Watanabe 174 Takuya Kuwahara 176 Dario Sarduy 177 Hiromasa Saito | |
| Catchers | 151 Sora Katoh | 171 Ryota Morishima | |
| Infielders | 122 Keio Fujino 124 Shuji Kuwahara 128 Daisuke Itoh 129 Kyoshiro Sakura 130 Haruki Katsuren 131 Koki Nakazawa | 149 Takuto Sakuma 153 Yoshiki Mishiro 159 Kyogo Yamashita 170 Ayuma Nishio 175 David Almonte | |
| Outfielders | 123 Shuya Ohizumi 144 Marco Simon 150 Keita Yamamoto | 166 Kaito Shigematsu 168 Kota Satoh 173 José Osuna | |
| Hokkaido Nippon-Ham Fighters | |||
| Pitchers | 113 Yamato Katoh 114 Ryodai Matsumoto 115 Shinji Saito 126 Terukazu Nakayama | 128 Kodai Yamamoto 137 Ren Kakigi 168 Koki Matsuoka 196 Sun Yi-Lei | |
| Infielders | 111 Taiki Hamada | ||
| Outfielders | 124 Kazuhiro Abe 125 Taisei Fujita | 127 Ataru Yamaguchi | |
| Orix Buffaloes | |||
| Pitchers | 003 Yuito Nakata 032 Kaito Iriyama 041 Hiroto Suga 042 Kaito Ohe | 043 Riku Miyaguni 044 Taketo Ashida 130 Taiki Ono | |
| Catchers | 034 Kyoichiro Murakami | ||
| Infielders | 045 Sota Kawano 124 Kyohei Ueno | 126 Kazuya Katsuki | |
| Outfielders | 004 Yamato Hirano 020 Takayuki Yamanaka | 123 Motohide Kinoshita | |
| Saitama Seibu Lions | |||
| Pitchers | 112 Kaito Awatsu 113 Sho Itoh 114 Towa Uema 115 Takeru Sasaki 116 Víctor López 120 Hiroki Inoue | 121 Daiki Miura 125 Sinclair 127 Ryosuke Moriwaki 129 Masahiro Kiwashimo 131 Shota Kise 136 Yuto Akagami | |
| Catchers | 122 Ryosuke Koresawa | ||
| Infielders | 118 Kazuki Nomura 126 Asahi Taniguchi | 130 Koji Kaneko 134 Ryota Kawano | |
| Outfielders | 119 Montell 123 Joseph | 135 Yuta Nakamigawa | |
| Tohoku Rakuten Golden Eagles | |||
| Pitchers | 017 Wang Yan-cheng 062 Naoto Nishiguchi 130 Kosei Koga | 138 Shinri Komine 155 Akihiro Takeshita | |
| Catchers | 022 Kei Mizukami | 137 Yuto Egawa | |
| Infielders | 131 Sotaro Nagata | 141 Kiyoharu Sawano | |
| Outfielders | 142 Ozora Yanagisawa | 144 Sho Okawara |
See also
- Nippon Professional Baseball
- List of current Nippon Professional Baseball team rosters
- Registration of players under control
- List of developmental players for the Nippon Professional Baseball (at Japanese-language Wikipedia)
External links
- - Japan Professional Baseball Players Association Official site (in Japanese)
- (in Japanese)