But this season's velocity readings have not been completely accurate for Halladay.
MLB.com gets daily reports from each ballpark with recent data trends to help calibrate its systems. Early in the season, those numbers can be skewed.
Pitch f/x's accepted range for speed bias is within 1 mph in either direction, above or below.
It has been greater than that in each of Halladay's starts.
April 5 at Pittsburgh: -2.07 mph.
April 11 vs. Miami: -1.35 mph.
April 16 at San Francisco: -1.81 mph.
The pitch f/x data has been an average 1.74 mph slower on days Halladay has pitched. Tack on an extra 1.74 mph and Halladay's velocity is almost the same as last season.
Phillies pitching coach Rich Dubee said he had not been concerned at all about Halladay's velocity, whether or not his fastball is averaging 90 mph or 92 mph.
"He's got four pitches," Dubee said. "He throws to both sides of the plate at any time. And overall he doesn't use the meat of the plate. That's what pitching is about. It isn't about velocity. Velocity allows you one thing. It might allow you to get away with some mistakes. But straight velocity without location, and velocity without an option of being able to go soft or go backwards as far as pure speed, those guys get waffled.
"And like most guys, he hasn't pitched in too good of a climate yet. Last night was a tough one. He got all heated up then sat for 20, 25 minutes [while the Phillies scored four runs in the top of the first inning]. The cold here, the wind, it's hard to get going and get the feel going again."
Interestingly, Halladay is striking out fewer batters early this season. He is averaging 5.5 strikeouts per nine innings, which is his lowest average since 2006 (5.4 strikeouts per nine innings). Halladay averaged 7.9 in 2010 and 8.5 in 2011.
Could that mean something?
"Approaches sometimes," Dubee said. "Guys try to hit early against him. Stuff like that. I'm not worried about strikeouts. Nope."
Dubee added one more thing.
"Look at swings," he said. "Look at swings off guys, the reaction to the assortment of pitches they have. I've seen guys throw 97, 98, and the swings are a whole lot different than somebody 91 or 92 with action, or 92 with separation of a split and a curveball. I've seen guys that just want to wing it up there at 97, 98. It gets loud fast."