"Baseball’s timeless appeal is predicated upon an equilibrium between pitching and hitting, and in the past, when that equilibrium has been thrown off..."

"... the game has always managed, either organically or through small tweaks, to return to an acceptable balance. But there is growing evidence that essential equilibrium has been distorted by the increasing number of pitchers able to throw the ball harder and faster... It’s one thing to identify velocity as the root cause of baseball’s inaction problem, but another thing to police it. You can’t legislate that pitchers can no longer throw above 95 mph.... The mound was placed at its current distance of 60 feet 6 inches from home plate in 1893.... [A] proposed rule [will] be tested in the independent Atlantic League... the mound will be moved back by two feet, to 62 feet 6 inches. The
thinking is that the added distance will give hitters more time to react to faster fastballs.... In 1893, when the mound was moved back 10 feet to its current distance, the change resulted in a 35-point jump in batting average and a 34-percent drop in strikeouts. By comparison, lowering the mound from 15 inches to 10 inches in 1969 resulted in more modest changes: an 11-point rise in batting average and a 2-percent drop in strikeouts. Some observers believe the hitter’s extra two feet of reaction time against fastballs would be offset by the additional distance for breaking balls to curve, drop or dart at the end of their trajectories — actually making it more difficult to hit, and thus giving baseball the opposite result of what it is looking for."

From "Velocity is strangling baseball — and its grip keeps tightening" by Dave Sheinin (WaPo).