When Jake Shields retires from mixed martial arts, he will do so as one of the greatest welterweights of all-time. The former Strikeforce, Shooto and EliteXC champion celebrates his 38th birthday on Jan. 9.

A two-time All-American wrestler at Cuesta College in San Luis Obispo, California, Shields made his professional MMA debut on Oct. 23, 1999 and never looked back. He went 11-4-1 across his first 16 appearances -- the run included an upset of Hayato Sakurai in Japan -- and captured the Shooto welterweight championship along the way. Between Nov. 12, 2005 and Oct. 23, 2010, Shields rattled off 15 consecutive victories, excelled in multiple weight classes and defeated a string of accomplished contemporaries: Martin Kampmann, Dan Henderson, Jason Miller, Robbie Lawler, Paul Daley, Mike Pyle, Carlos Condit and Yushin Okami.

Shields’ career-defining tear ended at UFC 129, where he lost a five-round decision to the incomparable Georges St. Pierre in a failed bid to claim Ultimate Fighting Championship welterweight gold. A Brazilian jiu-jitsu black belt under Cesar Gracie, he has gone 5-4 since, with wins over Yoshihiro Akiyama, Tyron Woodley, Demian Maia, Ryan Ford and Brian Foster offset by losses to Jake Ellenberger, Hector Lombard, Rousimar Palhares and Jon Fitch.

Others in MMA celebrating a birthday during the month of January:

JAN. 1

Guy Mezger (49)
Eiji Mitsuoka (41)
Charles Diaz (40)
Robbie Peralta (31)
John Lineker (27)
Herica Tiburcio (24)

JAN. 2

Mac Danzig (37)
Luis Santos (37)
Oli Thompson (37)
Emanuel Newton (33)

JAN. 3

Rodney Glunder (42)
Vlad Popovskiy (25)
Paddy Pimblett (22)

JAN. 4

Kimo Leopoldo (49)
Vladimir Matyushenko (46)
Shane Carwin (42)
Donny Walker (37)
Jose Maria Tome (35)
Derek Brunson (33)
Raphael Butler (33)
Jin Suk Jung (33)
Jung Min Kang (31)
Warlley Alves (26)

JAN. 5

Ruben Villareal (47)
Mike Bronzoulis (38)
John Gunderson (38)
Kaline Medeiros (38)
Trevor Smith (36)
Takahiro Suzuki (30)
Douglas Lima (29)
Goiti Yamauchi (24)

JAN. 6

Kevin Rosier (1962-2015)
Kalib Starnes (42)
Wilson Reis (32)
Matheus Nicolau Pereira (24)

JAN. 7

Christian Colombo (37)
Caros Fodor (33)
Thiago Santos (33)
Levan Makashvili (28)

JAN. 8

Tara LaRosa (39)
Andre Santos (36)
Ertan Balaban (34)
Michael Graves (26)

JAN. 9

Pete Spratt (46)
David Terrell (39)
Jake Shields (38)
Garreth McLellan (35)

JAN. 10

Yumiko Hotta (50)
Mickey Hughes (38)
Matt Brown (36)

JAN. 11

Rebecca Ruth (38)
Rafael Cavalcante (36)
Muhammed Lawal (36)
Eddie Alvarez (33)
Peter Sobotta (30)

JAN. 12

Ikuhisa Minowa (41)
Young Bok Kil (32)
Angela Hill (29)

JAN. 13

George Allen (50)
Leigh Remedios (41)
Justin Hawes (38)
Dennis Siver (38)

JAN. 14

Matt Uhde (43)
Akbarh Arreola (34)
Matt Riddle (31)

JAN. 15

Alexandre Franca Nogueira (39)
Nobuhiro Obiya (36)
Yuki Nishigo (32)
Andrew Craig (31)
Efrain Escudero (31)
Alexander Gustafsson (30)
Michael McDonald (26)
Zubaira Tukhugov (26)

JAN. 16

Paul Buentello (43)
Hyun Gyu Lim (32)
Chris Avila (24)

JAN. 17

Gary Goodridge (51)
Ariel Sexton (35)
Dusan Dzakic (30)
Brian Grinnell (29)
Alexander Sarnavskiy (28)
Arnold Allen (23)

JAN. 18

Neil Grove (46)
Jeff Monson (46)
Yoshikazu Fujiishi (39)
Luis Ramos (36)
Miguel Torres (36)
Carlos Diego Ferreira (32)
Marcin Held (25)

JAN. 19

Aritano Silva Barbosa (38)
Dustin Poirier (28)
Timur Valiev (27)

JAN. 20

Matt Ewin (47)
Alexandre Ribeiro (36)
Donavon Frelow (32)

JAN. 21

Francisco France (34)
Edson Barboza (31)
Patricky Freire (31)
Willie Gates (30)
Matthew Lopez (30)
Shane Campbell (29)

JAN. 22

Min Soo Kim (42)
Jorge Antonio Cezario de Oliveira (37)
Luigi Fioravanti (36)
Tomasz Drwal (35)
Ji-Hoon Kim (35)

JAN. 23

Tito Ortiz (42)
A.J. Matthews (29)
Christos Giagos (27)

JAN. 24

Akira Maeda (58)
Jamall Johnson (35)
Jimmy Spicuzza (32)

JAN. 25

Ron van Clief (74)
Jorge Gurgel (40)
Paulo Thiago (36)
John Quinn (34)
Mike Easton (33)
Dominique Steele (29)

JAN. 26

Dan Bobish (47)
Carmelo Marrero (36)
Rafaello Oliveira (35)
Chico Camus (32)

JAN. 27

Tony Sylvester (39)
Klay Konrad (35)
Anthony Pettis (30)

JAN. 28

Tim Boetsch (36)
Jesse Fujarczyk (34)
Brandon Saling (31)

JAN. 29

Stephen Palling (50)
Kazuyuki Miyata (41)
Annalisa Bucci (34)

JAN. 30

Rob Kimmons (36)
Jessica Penne (34)
Junior dos Santos (33)

JAN. 31

Akira Shoji (43)
Kengo Watanabe (41)
Maciej Jewtuszko (36)
Shunichi Shimizu (32)
Renan Barao (30)
Kirill Sukhomlinov (29)
Dhiego Lima (28)
Cesar Arzamendia (26)