According to the Baseball Almanac, his fastest pitch was clocked at 102 mph on August 27, 2005, at Safeco Field. He also has a slider, changeup, and a hard, sharp-breaking curveball. Jenks is third all-time in saves by a pitcher in a White Sox uniform.

Jenks was not able to play with his teammates at Timberlake High School, in Spirit Lake, Idaho or Inglemoor High School in Kenmore, Washington, because of poor grades. Jenks did play his sophomore year of high school for Lakeland High School before Timberlake High School was opened in 1998. Since Jenks was ineligible to play the remaining years of his high school career due to poor academic performance, he played in the Prairie Cardinals American Legion program where he dominated as both a pitcher and hitter. During his final season for the Prairie Cardinals, Jenks had 123 strikeouts in 92 innings pitched.

Jenks was drafted by the Anaheim Angels in the fifth round of the 2000 Major League Baseball Draft. In one minor league game, the radar gun clocked his fastball at 100 mph. During his time with the Angels organization, Jenks spent much of his time on the disabled list because of elbow trouble. Jenks' career with the Angels ended when he was designated for assignment by the team in December 2004.

Jenks was claimed off waivers by the Chicago White Sox for $20,000, and was sent to the club's Double-A affiliate, the Birmingham Barons. Jenks was called up to the major leagues by the White Sox on July 5, 2005. Jenks appeared in each game of the 2005 World Series, pitching a total of five innings, and making the series' final pitch. He recorded saves in Games 1 and 4, had a blown save in Game 2, and pitched scoreless 11th and 12th innings in the 14-inning Game 3. Jenks and Adam Wainwright of the 2006 St. Louis Cardinals are the only rookie closers to earn a save in the clinching game of a World Series.

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Wikipedia