© 2014 MLB Advanced Media, L.P. All rights reserved.

8/31/2014 7:25 P.M. ET

Chapman poised to set record for fastball velocity

PITTSBURGH -- Reds closer Aroldis Chapman's fastball has established its presence with authority since he broke into the Majors in 2010. But he's got a chance to do something that neither he, nor anyone else, has done before -- have a fastball average 100 mph for an entire season.

According to Fangraphs.com, Chapman's fastball has averaged 100.3 mph in 2014. Since the PitchF/x tracking system was installed in 2006, no pitcher has remained over 100 mph for an entire season, though Chapman was close with 99.6 mph in '10.

"At any point, I can't remember him coming in and throwing with that consistent velocity, game-in and game-out, 99-102 almost every single game," Reds manager Bryan Price said on Sunday.

Earlier in his career, Chapman's velocity would dip below 100 if he worked back-to-back days, and especially three days in a row. This season, he's been mostly durable and though he's mixed in more changeups and sliders, his fastball has remained more often in triple digits.

Just how often, exactly? According to BaseballSavant.com, there have been 14 Major League pitchers who have reached 100 mph this season on a combined 469 pitches. Entering Sunday, Chapman had thrown 325 of those pitches. He had thrown 767 pitches over 43 appearances, meaning 42 percent of his total pitches have been 100 mph or higher.

The second most, from the Royals' Kelvin Herrera, was 46 pitches at 100 mph or more. Reds reliever Jumbo Diaz touched 100 mph once.

Price noted that Chapman used to throw 40-45 pitches to get loose as a rookie, and the closer is now conditioned to get ready within 15-20 warmup pitches.

"I think there is probably a maturation process to how to get loose, how not to do too much before a game, when to long toss, when not to long toss and how to be ready to post up every day as a relief pitcher," Price said. "It's certainly a learned craft."

Hamilton ties Reds rookie stolen base record

PITTSBURGH -- It appears that a Reds rookie stealing 54 bases happens only once a century. In the seventh inning of Sunday's 3-2 victory over the Pirates, Reds center fielder Billy Hamilton swiped second following an infield single. It gave Hamilton 54 stolen bases, tying the 105-year-old rookie record set by Bob Bescher in 1909.

Bescher also holds the Reds' single-season stolen base record of 81, set in 1911.

Before the game, Hamilton was not aware he was on the verge of setting a club record.

"It's not about records or numbers ... you want to win," Hamilton said. "Records are good things, but I realize the year I tried to break the record in Double-A (155 steals in 2012), I was thinking about it so much that it actually slowed me down. I went back to playing the game and it just happened."

Hamilton's stolen base total is the most for any Reds player since Deion Sanders swiped 56 bases in 1997.

Worth noting

• Reds infielder Ramon Santiago turned 35 on Sunday.

Mark Sheldon is a reporter for MLB.com. Read his blog, Mark My Word, and follow him on Twitter @m_sheldon. This story was not subject to the approval of Major League Baseball or its clubs.