# Developmental player system (Nippon Professional Baseball)

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.
Holders of league titles and awards from developmental players :
| 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 Takeuchi202 Frank Álvarez204 Tubasa Kato205 Kenshin Kakigoshi208 Sho Ishikawa | 210 Toshiya Okada212 Tensho Nonaka213 Akio Moriyama214 Ren Kondoh216 Towa Kikuta |
| Catcheres | 215 Toki Hiwatari | |
| Infielders | 207 Mao Hoshino | 218 Rii Kawakami |
| Outfielders | 211 Yuma Fukumoto | 220 Carlos Monier |
| Hanshin Tigers |||
| Pitchers | 122 Ippei Ogawa123 Kai Matsubara125 Ryo Itoh | 131 Jose Betances132 Anthony Martinez |
| Outfielders | 126 Kein Fukushima | |
| Hiroshima Toyo Carp |||
| Pitchers | 120 Takeru Sugita122 Rei Sakata125 Taiga Tsuji | 126 So Shinya128 Mirai Sugihara129 Raisei Nakamura |
| Infielders | 127 Seita Maekawa | 130 Moises Ramírez |
| Outfielders | 121 Norihiko Nabara | 131 Nelson Robert |
| Tokyo Yakult Swallows |||
| Pitchers | 012 Hiroki Kondo013 Kota Katekaru015 Shohei Numata | 016 Yusei Nishihama017 Shosei019 Shinnosuke Shimo |
| Catchers | 025 Felipe Kisu | |
| Infielders | 026 Sota Takano | |
| Yokohama DeNA BayStars |||
| Pitchers | 101 Haruto Kusano 102 Manato Shimizu105 Wilny Moron106 Aki Watanabe | 107 Hansel Marcelino108 Ryuto Konno110 Alexander Martínez122 Haruto Shoji |
| Catchers | 116 Ryuhei Kuki | 130 Taiga Kondoh |
| Infielders | 100 Ren125 So Ogasawara133 Ryunosuke Aibara | 144 Daichi Kobukata193 Ikumi Takamizawa |
| Outfielders | 103 Nagi Murakawa | |
| Yomiuri Giants |||
| Pitchers | 011 Naoki Kasashima012 Katsunari Miura015 Haruto Kawasaki016 Takahiro Chiba018 Motoya Kinoshita019 Junki Sonoda 020 Natsuki Toda021 Kenta Onuma023 Tomoki Tamura | 026 Yusefu Yoshimura028 Ryu Tomida030 Yusuke Yamasaki034 Tessei Morimoto035 Elvis Luciano041 Huang Chin-hao047 Eiji Kamouchi063 Yuki Hanada |
| Catchers | 006 Hayato Sakamoto010 Ryoya Ohtsu022 Keita Kameda | 024 Kenki Maeda069 Tetsu Hagiwara |
| Infielders | 001 Ren Kato004 Gen Murayama005 Yuya Tanoue007 Kisara Utsunomiya | 008 Hakuto Aizawa025 Hiroto Okamoto027 Rio Kitamura |
| Outfielders | 003 Yamato Suzuki009 Misaki Sasahara013 Julian Tima031 Rui Mitsuka | 033 Kota Hirayama037 Marek Chlup044 Gen Ohshiro051 Hidetora Funakoshi |

### Pacific League

| Position | Players | source |
| Chiba Lotte Marines |||
| Pitchers | 120 Fuki Tanaka121 Seiya Dohi124 Takuro Furuya125 Kirato Nagashimada | 127 Yuto Yoshikawa128 Kaiki Shirahama133 Ryota Takeuchi |
| Catchers | 126 Ryosuke Murayama | 137 Konoshin Tomiyama |
| Infielders | 129 Rui Katsumata130 Kaisei Kurokawa | 134 Shinya Matsuishi |
| Outfielders | 135 Hikaru Kohno136 Kazuki Fujita | 138 Andy Martin |
| Fukuoka SoftBank Hawks |||
| Pitchers | 120 Hiroki Sato125 Yuri Furukawa126 Yuwa Miyasato133 Kotaro Hoshino134 Shinno Ohshiro135 Alexander Armenta136 Fuga Otake139 Sanshiro Izaki141 Mailon Felix142 Haruto Fujiwara143 Shun Murakami145 Reiri Tanaka146 Jumpei Fujita147 Koki Kato148 Takuma Yamasaki152 Masaki Takimoto | 154 Takuma Sato156 Luis Rodríguez157 Jui Kobayashi158 Ren Akaba160 Keishin Nagamizu161 Kaito Uchino162 Junpei Okaue163 Akito Sasaki164 Sota Mizuguchi165 Hayato Miyazaki169 Yusei Tobita172 Yuki Watanabe174 Takuya Kuwahara176 Dario Sarduy177 Hiromasa Saito |
| Catchers | 151 Sora Katoh | 171 Ryota Morishima |
| Infielders | 122 Keio Fujino124 Shuji Kuwahara128 Daisuke Itoh129 Kyoshiro Sakura130 Haruki Katsuren131 Koki Nakazawa | 149 Takuto Sakuma153 Yoshiki Mishiro159 Kyogo Yamashita170 Ayuma Nishio175 David Almonte |
| Outfielders | 123 Shuya Ohizumi144 Marco Simon150 Keita Yamamoto | 166 Kaito Shigematsu168 Kota Satoh173 José Osuna |
| Hokkaido Nippon-Ham Fighters |||
| Pitchers | 113 Yamato Katoh114 Ryodai Matsumoto115 Shinji Saito126 Terukazu Nakayama | 128 Kodai Yamamoto137 Ren Kakigi168 Koki Matsuoka196 Sun Yi-Lei |
| Infielders | 111 Taiki Hamada | |
| Outfielders | 124 Kazuhiro Abe125 Taisei Fujita | 127 Ataru Yamaguchi |
| Orix Buffaloes |||
| Pitchers | 003 Yuito Nakata032 Kaito Iriyama041 Hiroto Suga042 Kaito Ohe | 043 Riku Miyaguni044 Taketo Ashida130 Taiki Ono |
| Catchers | 034 Kyoichiro Murakami | |
| Infielders | 045 Sota Kawano124 Kyohei Ueno | 126 Kazuya Katsuki |
| Outfielders | 004 Yamato Hirano020 Takayuki Yamanaka | 123 Motohide Kinoshita |
| Saitama Seibu Lions |||
| Pitchers | 112 Kaito Awatsu113 Sho Itoh114 Towa Uema115 Takeru Sasaki116 Víctor López120 Hiroki Inoue | 121 Daiki Miura125 Sinclair127 Ryosuke Moriwaki129 Masahiro Kiwashimo131 Shota Kise136 Yuto Akagami |
| Catchers | 122 Ryosuke Koresawa | |
| Infielders | 118 Kazuki Nomura126 Asahi Taniguchi | 130 Koji Kaneko134 Ryota Kawano |
| Outfielders | 119 Montell123 Joseph | 135 Yuta Nakamigawa |
| Tohoku Rakuten Golden Eagles |||
| Pitchers | 017 Wang Yan-cheng062 Naoto Nishiguchi130 Kosei Koga | 138 Shinri Komine155 Akihiro Takeshita |
| Catchers | 022 Kei Mizukami | 137 Yuto Egawa |
| Infielders | 131 Sotaro Nagata | 141 Kiyoharu Sawano |
| Outfielders | 142 Ozora Yanagisawa | 144 Sho Okawara |