Other creative approaches to advancing our understanding of age–work
performance relations also have emerged in recent years. For example, Schulz,
Musa, Staszewski, and Siegler (1994) examined lifetime performance patterns
of professional baseball players. Here too, performance on average appears
to peak at different ages for different competencies. For example, most measures
of batter performance (e.g., home-runs, stolen bases, best batting average)
peak at about age 27. However, strike-out percentage and base-on balls
peak at age 28. Fielding average peaks at age 30. Pitchers have their best
strike-out seasons at age 27 but experience their best ERA’s at age 29. The
pattern for elite players (Hall of Famers), however, exhibits fascinating differences
from the norm. At each age, they excel, but their peak performances
are generally experienced 1–5 years later than the average player. The authors
note that those skills which depend more on pure power or speed (physiological
capacity) are the first to peak, whereas skills with a greater experience
and judgment component appear to continue to improve over a longer period
(Schulz et al., 1994). Here too, however, it is important to consider individual
differences in age-related patterns of ability or performance. A focus on
average performance can often mask significant patterns of intraindividual
change over time. For example, a longitudinal analysis of the batting and
earned-run averages of career batters and pitchers revealed a substantial percentage
of players whose performance consistently improved and a large
number whose performance steadily worsened over a period of 7 to 10 years
(Hofmann, Jacobs, & Gerras, 1992).