Are Their Days Numbered?

Take the case of Mark Fidrych . In 1976, when he was 21, he went 19-9 with the fifth-place Detroit Tigers and was named the American League 's Rookie of the Year. Even Palmer, who beat him out for the Cy Young Award that year, marveled at the Bird. "You knew what he was going to do; you just couldn't beat him," says Palmer. "He'd throw that 90-mile-per-hour sinker, and the shortstop would scoop up the grounder. Fidrych made pitching look very simple when it wasn't. I used to sit in the dugout and watch him and think, Wouldn't life be great if I were Mark Fidrych ."

The next year, the Bird got off to a blazing start, winning six of his first eight starts. Then, on July 4th in Baltimore , while making his ninth start, Fidrych felt a twinge in his right shoulder. After that fateful day, he pitched only 18 more games in the majors.

What went wrong? According to Wright, disaster was inevitable because Fidrych threw too long and too hard at too early an age. At the start of his dream season, Fidrych had pitched in only 53 games as a pro. But he was so successful that year that he ended up with a total of 250 innings.

Work load, however, is affected by more than innings pitched and days of rest between starts. Fidrych usually worked out of a five-man rotation, but he also pitched deep into almost every start, shouldering the load expected of an ace. As a result, he put together 24 complete games in only 29 starts. Last year the entire Cincinnati Reds staff had only 24 complete games. Fidrych may not have known it, but he was exceeding his fatigue level virtually every game he pitched.

Wright's way of measuring how frequently pitchers work deep into their starts is to calculate the average number of batters faced per start (BFS). That can be done by multiplying a pitcher's innings pitched for a season by three, and then adding the number of hits and walks he allowed and dividing that number by games started. Wright counts the odd relief appearance as half a start. Although errors by the pitcher's team can add to the number of batters faced. Wright ignores them as insignificant. A high BFS indicates not just that a pitcher threw a lot of pitches—a BFS of 30.0, for example, is roughly equivalent to 105 pitches—but that he also tended to work deep into his starts.

In '76, Fidrych's BFS was 34.0, one of the highest of any 21-year-old pitcher in history. By contrast, Ryan didn't surpass 30.0 until he was 25. A strong, stocky pitcher can generally handle more work than a slender finesse artist. Regardless of physique, a BFS of 30.0 is dangerous for teenagers and for most pitchers in their early 20's.

Then there's Larry Dierker . At age 22 in 1969, he was 20-13 with a 2.33 ERA for the Houston Astros . But he pitched 305 innings and had a BFS of 32.3. By the time he was 30, he was washed-up (chart, page 64).

And Dave Rozema ? He was a 20-year-old rookie for the Tigers in 1977, when he went 15-7 with a 3.10 ERA. He had a 32.5 BFS with 218 innings pitched. Rozema stayed in the majors until 1986, but he never again won more than nine games.

On the other hand Don Sutton threw 226 innings in 1966 as a 21-year-old rookie, but the Los Angeles Dodgers didn't work him too hard, so he had only a 25.5 BFS. He retired last year with 324 wins. Similarly, a major reason that Whitey Ford performed so well for so many years is that he missed the 1951 and '52 seasons, when he was 22 and 23, to serve in the Army during the Korean War. Ford came into his own after the war and was still going strong at 34, when he led the American League in victories for the third time with 24.

Wright's theory even seems to hold up with pitchers from the early days of baseball. For instance, why was Hall of Famer Eddie Plank one of the only pitchers from the Dead Ball Era (pre-1920) to excel after age 35? Because, Wright argues, Plank didn't pitch professionally until he was 26, in 1901. Plank was such an economical pitcher that he hated to throw to first base to keep runners close to the bag. He had his best year (26-6 with a 2.22 ERA) when he was 36. And in his final season five years later, his ERA was 1.79.