Glossary of baseball (J)



The run the pitcher takes from the mound to first base in order to cover for the first baseman who has just fielded the ball.[citation needed]


A home run or to hit a home run. "Hitting a jack" or "Jacking one out of here".


Half-hearted or lazy effort by a player, i.e. "He jaked that play."


  • To pitch far enough inside that the batter is unable to extend while swinging. "The pitcher jammed the batter." The batter was "handcuffed" or "shackled" by the pitch.
  • When runners are in scoring position with less than two outs and good hitters coming up. "The pitcher is in a jam."
  • The "bases are jammed" (or loaded or full) when there are runners on all three.

janitor throwEdit

When an outfielder, trying to throw hard, spins or falls down.

jelly legsEdit

A batter's legs are "made out of jelly" when he departs from a good stance. "His curve ball ... it jelly-legs you." - Phillies First Baseman Jim Thome, referring to Barry Zito's curve.[1]


To hit the ball hard, typically used to refer to pulling the ball over the fence for a home run. "Derrek Lee jerked one of his patented doubles into the left-field corner to lead off the fourth against Minnesota lefty Johan Santana, the reigning Cy Young winner."[2]


A Punch and Judy hitter who hits with little power.


  • "Bases juiced" means bases loaded.
  • A player who is said to be juiced is thought to be taking performance-enhancing drugs. "It is now assumed, of course, that Bonds may well have been juiced on steroids at the time; the previous year he had set the all-time single-season record of 73 home runs, and his musculature was almost freakishly swollen."[3]
  • A baseball that is juiced has been modified in some way that makes it travel farther when hit. "Spectacular increases in home runs have often raised the question: Has the ball been juiced up to travel farther, in order to increase the number of home runs?"[4]


  • A fielder is said to get a good jump on the ball when he anticipates or reacts quickly to a batted ball and is thereby able to make a good play by fielding or catching it.[5] Also see crack of the bat.
  • A baserunner gets a good jump when he is able to leave the base well before the pitch reaches the plate. "Upsetting the timing of the baserunner can effectively prevent him from getting a good jump ... Base runners often read a pitcher's look and get their jump, or start, based on the pattern the pitcher establishes."[6]

Junior CircuitEdit

The American League, so-called because it is the younger of the two major leagues. The American League was founded in 1901, while the National League – the Senior Circuit – was founded in 1876.


breaking balls and knuckleballs, pitches that are hard to hit due to movement rather than velocity. "I couldn't believe he threw me a fastball because he had me down 1-2", Thames said. "He's usually a junk pitcher and he tried to sneak a fastball past me, and he left it up."[7] See also: Eephus pitch

junkball pitcherEdit

A pitcher who throws predominantly junk, usually due to a weak (or slow) fastball. A junkballer or a junk artist: "Like all junk artists, Trujillo will have to prove himself at the higher levels before getting a shot at a major league job."[8] See also: Eephus pitch


  1. ^ "Barry Zito Quotes". Retrieved 2019-04-05.
  2. ^ Rogers, Phil (2005-07-13). "American beauty". Chicago Tribune. Retrieved 2019-04-05.
  3. ^ Robinson, Eugene (2007-12-18). "Fans on the Juice". The Washington Post. Retrieved 2019-04-05.
  4. ^ Sowell, Thomas (2001-12-30). "Was the ball juiced?". Townhall. Retrieved 2019-04-05.
  5. ^ See Allan R. Andrews, "A Good Jump on the Ball: Algorithm in the Outfield", The American Reporter (8 October 1998).
  6. ^ Jack Stallings and Bob Bennett, Eds., Baseball Strategies: Your Guide to the Game within the Game, American Baseball Coaches Association, 2003, p. 125.
  7. ^ "Granderson's homer, Thames' slam power Tigers' win". 2007-07-07. Retrieved 2019-04-05.
  8. ^ John Sickels Baseball Newsletter (June 15, 2001).