John Smoltz is all in on the MLB's new rule changes ... telling TMZ Sports he thinks they're going to have a huge, positive impact on the game.
"With the rule changes to get the game action-packed again," the Braves legend said, "I think it's going to be phenomenal."
The league introduced a slew of new regulations for 2023 ... putting a timer on pitchers and hitters, making bases bigger and banning teams from implementing defensive shifts in their infields.
They've only been in place for two days (outside of spring training) .