In the opening days of December 2000, the Rockies went on a free-agent pitching splurge, initially signing Denny Neagle to a five-year, $51.5 million deal, and then giving left-hander Mike Hampton a record-setting eight-year, $121 million deal.

"We added a horse," then general manager Dan O'Dowd said in reference to Hampton, who had racked up a National League-leading 22 victories in 1999 with the Astros while going 63-31 from 1997-2000.

It became another chapter in a learning process for the Rockies, underscoring the fact that proven big league pitchers struggle to survive at Coors Field.

It's why when the Rockies read or hear media types suggesting big-name free-agent pitchers they might pursue or possible trades for established starting pitchers, they have learned to smile and ignore the chatter.

Yes, Coors Field is a difficult place to pitch and succeed, and over time what has been underscored is those who are successful as starting pitchers at Coors Field are either homegrown prospects, who as longtime Colorado pitcher Aaron Cook explained "come up here with something to prove, welcoming the challenge," or journeymen starting pitchers who are more concerned with winning than the stats on a baseball card.

Oh, there was an initial hope in that 2001 season. Hampton went 5-0 with a 3.10 ERA in his first six Coors Field starts, sparking talk that with his hard sinker he could master the challenge of the Mile High altitude.

Hampton would make only 20 additional starts at Coors Field, going 7-9 with a 6.39 ERA, before eventually being included in a three-team trade that sent him to the Braves, with the Rockies paying $48.5 million of his remaining salary.

Neagle, meanwhile, won six of his first eight decisions with the Rockies, but was 19-23 with a 5.57 ERA overall for Colorado before being released with two years remaining on his contract.

Hampton and Neagle are not isolated cases. There have been 21 pitchers who made at least 25 starts at Coors Field in its 21 years of operation, and only 12 of them have a winning record in the ballpark.

Hampton is among six of those pitchers whom the Rockies acquired in a trade or signed as a free agent, going 12-9 overall, but after that 5-0 record in his first six starts, it was mostly downhill from there.

The other five were either inexperienced or journeyman:

• Jorge De La Rosa came to the Rockies after beginning his big league career with the Brewers and Royals, compiling a 15-23 record. The left-hander is 86-61 with a 4.35 ERA in nine seasons for Colorado.

• Josh Fogg was 39-42 before two stints with the Rockies from 2006-09, during which he went 21-20 with a 5.05 ERA.

• Tyler Chatwood was 6-11 as a rookie with the Angels before being dealt to the Rockies after the 2011 season. The righty is 26-20 with a 3.97 ERA over four seasons with Colorado.

• Kevin Ritz compiled a 6-18 record over four seasons in Detroit before going 39-38 with a 5.20 ERA for Colorado from 1994-98.

• Pedro Astacio was 53-48 with a 5.43 ERA in five seasons after being acquired from the Dodgers, for whom he was 48-47.

Meanwhile, homegrown Rockies with success at Coors in 25 or more starts include Chad Bettis (13-7), Ubaldo Jimenez (30-19), Juan Nicasio (13-9), Jason Jennings (31-22), Jeff Francis (34-29) and Cook (36-32).

And the four returning members for Colorado's rotation -- Jon Gray (7-3), Bettis, Chatwood (14-12) and Tyler Anderson (5-2) are a combined 39-24 at Coors Field.

By contrast, the high-profile pitchers the Rockies have brought to Coors Field have struggled.

In addition to Hampton and Neagle, Colorado's free-agent efforts included the signing of Bill Swift (8-4, but only 18 starts in three seasons) and Darryl Kile (10-12 in two seasons).

In total, the four high-priced free agents have accounted for only two of the 41 seasons in which a Rockies pitcher has won 10 games or more (home and away). Hampton was 14-13 in 2001, tied for 12th; and Kile was 13-17 in 1998, tied for 17th on Colorado's single-season victory list.

The numbers tell a story that the Rockies can't ignore.

Outsiders can campaign for them to make a splash on the free-agent market or in a trade. History, however, has underscored the risk has no reward.

Tracy Ringolsby is a columnist for MLB.com.