Among the various explanations for the five shutout innings Smoltz pitched -- highlighted by nine strikeouts -- was that he and the Cardinals believe he may have stopped tipping his pitches to opposing hitters, particularly when he pitched from the stretch. The Cardinals' staff had the right-hander make an adjustment following a bullpen session he threw on Thursday, and the results were hard to argue with.
"It's pretty clear he was tipping his pitches," manager Tony La Russa said after the game.
St. Louis has something of a history with this. It's one of the things the club's staff looks for when trying to "fix" a pitcher, and there was some statistical evidence to back up the claim as well. With runners on base, Smoltz's numbers in Boston were far worse than with the bases empty -- batters had a 63-point higher batting average and a 123-point uptick in slugging percentage.
Additionally, tipping might explain why Smoltz's performance got worse as he got deeper into games. Opponents fared much better in their second and third turns through the batting order than the first time around.
Smoltz himself pointed more to a mechanical adjustment he made, getting his heel closer to the pitching rubber when he pitched. But he also acknowledged that he might have been giving something away to hitters.
"I very well could have been," he said. "If you tip your pitches, it's a lot easier to hit in this league."
Smoltz will start again on Friday against the Nationals in St. Louis.
Matthew Leach is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.