The next time you see Todd Helton take a crack with the bat, you might note that the Colorado Rockies' first baseman has a career that has almost doubled the average of a Major League Baseball player, according to new study by a University of Colorado at Boulder research team.

The study, which reviewed voluminous baseball statistics beginning in 1902, revealed that position players havecareersthat span only 5.6 years in average and that one in five position players will have only a single-year career. Helton, on the other hand, made his Rockies' debut (he's never played for another Major League club) on Aug. 2, 1997.

Overall, there's more than an 11 percent chance that each year will be the last for any one major leaguer, according to the study, Major League Baseball Career Length in the 20th Century, which will be published in the August issue of Population Research and Policy Review. The study was conducted by former CU-Boulder graduate student William Witnauer, sociology Professor Richard Rogers and doctoral student Jarron Saint Onge. Rogers also directs the Population Program in the CU-Boulder Institute of Behavioral Science.

But as many fans would be able to say definitively, the chances are highest that a player won't last more than one year, Rogers said. The exit rate in the first year (of a player's career) was about 20 years; the second year is about 18 percent," he said.

"The exit rate declines to a low point of 11 percent in the seventh year, and then it begins to slowly climb again," he said. "By the 20th year, it's 35 percent, and in the 22nd year it was 52 percent.

The study examined the career statistics of baseball players who started their careers between 1902 and 1993. Pitchers were excluded because of their unique positions, career volatility and propensity for injuries.

Between 1902 and 1993, 5,989 position players started their careers and played 33,272 person years of Major League Baseball. Using those considerable statistics, the authors then developed a table of average career lengths for the players.

"Everyone knows that Major League Baseball is highly competitive," Witnauer said. "But as Americans enjoy this year's All-Star game, they now have a definitive answer on the average length of a baseball career."

For the baseball history buffs, the study also provide some insight into three different eras of baseball, Rogers said.

In the Early Era, from 1902 to 1945, players had a career expectancy of 4.3 years. In the Golden Era, from 1946 to 1968, players had a career expectancy of 6.47 years.