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The break on the pitch is shorter than that of a curveball. The release technique of a slider is between a curveball and a fastball. The slider is similar to the cutter, a pitch which is thrown as a fastball, but differs in the sense that a slider tends to be more of a breaking ball.
Slider continuum 
Depending on velocity, a pitch can fall anywhere on the continuum from "fastball" to "slider":
- fastball » cut fastball » hard slider » slider » slurve
- cut fastball: 3–5 MPH slower than fastball
- hard slider: 5–7 MPH slower than fastball
- slider: 7–9 MPH slower than fastball
The most notable difference between a slider and curveball is that the curveball delivery includes a downward yank on the ball as it is released, in addition to the lateral spin applied by the slider grip. The slider is released off the index finger while the curveball is released off the middle finger. If the pitcher is snapping his wrist as he throws, and the movement is more downward than sideways, then he is probably throwing a curveball or slurve, and not a true "slider". When throwing a slider the pitcher should create a "dot" on the baseball. What this means is that as the ball approaches home plate the rotation of the ball is forming a dot. On a good slider the "dot" will be down where it is not noticeable for a hitter to pick up. From the batter's perspective this dot appears white, whereas the dot is red for a curve ball (created by the seam movement) allowing many skilled batters to immediately recognize the type of pitch. By having the dot on the bottom part of the ball the pitcher will create good depth to the pitch. A good hard slider has a slight break across the plate and a slight drop on its plane to the hitter.
It is important when throwing a slider, or any breaking pitch in baseball, not to come "around" the baseball. When the pitcher comes "around" the ball the pitcher puts extra tension on his pitching arm to throw that pitch. As mentioned earlier the pitcher should create a dot on the ball when throwing a slider, but the dot is not created by sweeping the arm around and spinning the ball. The dot will be created with a regular arm motion, just like a fast ball, then at the end the pitcher should turn their wrist so that their thumb is facing downwards. It is important that the dot is on the bottom half of the ball or else the slider will have little depth to it. To make sure that the dot is on the bottom the pitcher must ensure that the fingers stay on top of the ball until release. A good way to remember this is for the pitcher to tell himself to throw his fingers at the catcher. With the slider, or any pitch for that matter, it is important to follow through and finish the pitch.
Notable sliders 
Right-handed pitcher David Cone was famous for his devastating slider, which he was able to use many different ways, as was Bob Gibson of the Cardinals. To right-handed batters, Cone would throw it to hook sharply outside the strike zone, getting hitters to chase and miss it. He would also throw the pitch from various arm angles to further confuse the hitter. Cone's slider was also a strikeout pitch to left-handed hitters, throwing it to curve back over the outside corner and catch the hitter looking. Cone used the slider to great effect during his perfect game on July 18, 1999—the final out was recorded via a slider resembling a whiffle ball. In the first game of the 1988 World Series, Dennis Eckersley tried to strike out Kirk Gibson with a slider, but Gibson was sitting on that pitch and hit a game-winning home run. A notable slider was thrown by John Smoltz which would come in looking like a strike and then break out of the strike zone. Brad Lidge featured a devastating slider as his primary weapon in his perfect season as a closer in 2008, and used a slider to strikeout the final batter of the 2008 World Series for the Philadelphia Phillies. Closer Francisco Cordero also possesses a potent slider. Yet another notable pitcher who throws a slider is Hall of Famer Rollie Fingers who used the pitch to win a Cy Young Award in 1981. Another potent slider was thrown by Seattle Mariners and Arizona Diamondbacks starter Randy Johnson, whose incredible lateral movement on the pitch eventually spawned its own nickname, "Mr. Snappy". At times, his slider was faster than most pitchers' fastballs. Hall of Fame pitcher Steve Carlton was known for his nearly unhittable slider. Mike Jackson, who tied Paul Assenmacher with the most games pitched in the 1990s (644), also threw a great slider. Ron Guidry was famous for his devastating slider, he was taught by Sparky Lyle.
Other active pitchers with good sliders include Sergio Romo, Joe Nathan, Joba Chamberlain, Cliff Lee, Johan Santana, Carlos Mármol, Josh Johnson, Scott Feldman, Brad Lidge, Clayton Kershaw, Al Alburquerque, and Francisco Liriano. Armando Galarraga threw sliders 38.9% of the time in 2008, more than any other starting pitcher in the majors, and Ryan Dempster threw them 32.9% of the time, more than any other NL starting pitcher. In 2008 CC Sabathia had the most effective slider, among major league starting pitchers. Zack Greinke won the AL Cy Young award in 2009 due in large part to his slider, one of the better pitches in all of baseball. In 2011, Clayton Kershaw won the Triple Crown by having a .117 average against his slider.
The innovator of the slider is debated, but some credit Chief Bender as the first to use the slider, also George Blaeholder was credited with using it with the St. Louis Browns then called a "nickel curve", in the 1910s. Bender used his slider to help him achieve a no-hitter and win 212 games in his career. Bender was the first pitcher to win six World Series games.
More recently, New York Yankee pitcher Ron Guidry mastered the pitch to great effect in 1978 when he went 25–3 and won the Cy Young Award. It is also the name of the Cleveland Indians mascot who was recently inducted into the Mascot Hall of Fame.
|Wikimedia Commons has media related to: Sliders (pitch)|
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- Smith, Cameron. "Baseball Insider - The Best Pitch in Baseball: Greinke's Slider?". Voices.washingtonpost.com. Retrieved 2012-05-27.
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