He did not permit bunts.

“He did not permit bunts—bunts, that is, by players who wanted a base hit and were afraid to swing away at him. A bunt to advance a runner was permissible; a bunt for a hit was not. He reciprocated by throwing at the player the next time he came up.”

That is just one part of David Halberstam’s long description of what Bob Gibson did not permit, from October 1964.

Bob Gibson hit like a second baseman, fielded like a shortstop, and pitched like a linebacker. They’d better not allow him near the switch that controls lightning strikes.