Master · 1959-1975 · right-handed

Bob Gibson

The most feared arm of his era, who pitched as though the plate were his to defend.

Signature pitchSlider

Gibson did not negotiate with hitters. He worked from a low three-quarter slot and an explosive fall toward first base, and he treated the strike zone as territory he owned. The slider was the put-away pitch, including a back-up version that started inside on a same-handed hitter and bent back over the plate, the opposite of what the eyes told the batter to expect.

The signature pitch

His slider, thrown hard, was the strikeout pitch; the famous "back-up slider" started in on a same-handed hitter and swept back over the plate, breaking the wrong way on purpose. The final out of his record 17-strikeout 1968 World Series Game 1 was Willie Horton frozen on that pitch.

Secondhand, attributedCBS Sports, Bob Gibson's back-up slider

Described by CBS Sports from film of the back-up slider; the grip itself is not documented in a reachable source, so none is asserted.

Study the slider

Slider04

Reference schematic

Driveline's common grip holds the two fingers close together and slightly off-center, the middle finger on or just inside a seam, the index on the leather, thumb supporting underneath, with the cue to let the ball slide off the hand.

Source: Reputable analysis

Open specimen

The mental edge

He wanted to own the outside corner; the only reason to throw inside, he said, was to keep a hitter from leaning out over the plate. He framed his reputation as intensity rather than anger, and called pitching roughly ninety percent mental.

Reputable analysisFanGraphs, Remembering the Intense and Indomitable Bob Gibson

Paraphrased from the FanGraphs appreciation, which quotes Gibson on owning the outside half. The knockdown was part of the toolkit: he listed "knockdown, brushback, and hit-batsman" among his nine pitches.

“The part of pitching that separates the stars from everyone else is about 90 percent mental. That is why I considered it so important to mess with a batter’s head without letting him inside mine.”

Secondhand, attributedWikipedia, Bob Gibson

Gibson's own phrasing, but reachable only through the Wikipedia biography — no primary interview, autobiography passage, or transcript placing this exact sentence in his direct words was located. The label reflects the secondary pathway, not doubt about the sentiment.

The record

The summer of 1968 is the file. He allowed earned runs at the stingiest rate any starter has managed in the live-ball era, won twenty-two games and finished thirteen of them as shutouts, and was so thoroughly unhittable that the league lowered the mound the following spring — partly because of him.

Official dataNational Baseball Hall of Fame, Gibson's 1968 season/ 1968

That October he opened the World Series by striking out seventeen Tigers, still the record for a single Series game, and froze Willie Horton on the back-up slider for the last of them.

Official dataCBS Sports, Bob Gibson's back-up slider

The numbers live with the record-keepers.

Baseball-Reference, Bob Gibson — the full record

The record is told here the way the rest of the atlas is told: in prose, each claim confidence-labeled and one click from its source. Where reputation and record disagree, the gap is shown, not smoothed over.