Trenton Times, Jan '91
Title: Kaplan's project might change face of baseball
* 1988 Graduate of Lawrence High School
* Junior at Cal Tech in Pasadena, Cal.
* Engineering and applied sciences major spent last summer as intern for the Baltimore Orioles, working in the computer programming department and filing reports on all active professional players.
* Has created a new stat, relievers effectiveness (RE), which is the number of inherited runners a relief pitcher allows to score divided by the number expected to score.
By: RICK FREEMAN, staff writer

Ari Kaplan is a former Lawrence High student who is now a junior reserver outfielder for the Cal Tech baseball team in Pasadena, Calif. Nothing unusual there; many area athletes have plied their talents between the white lines in the collegiate ranks.

What makes Kaplan a bit different, however, is what he accomplishes in baseball off the field. For it is away from the diamond that the 20-year-old engineering and applied sciences major is likely to make his mark in the National Pastime.

Kaplan spent last summer as an intern for the Baltimore Orioles, working in the computer programming department and filing reports on all active professional players. Along with Jim Klein, the computer services director, Kaplan wrote the computer program the Orioles' organization uses to compile those reports.

But Kaplan's future in the game, it would seem, lies in a much larger area than just writing computer programs and typing information into a machine. Much like Bill James and the people from the Elias Sports Bureau, Kaplan's statistical revelations could very well change the way people view the game.


"There's a program at Cal Tech called SURF - the Summer Undergraduate Research Fellowship," Kaplan said about what transpired after his freshman year in 1989. "SURF sponsors students for various research, almost all related to sciences, but my brother (Todd, now 22) told me Cal Tech was really lenient on creative ideas that had decent credibility, so I decided to give it a shot - researching baseball, focusing on history of the game and its statistics."

The history part of Kaplan's thesis, entitled "How Do You Spell Relief? An Analysis of Baseball Pitching, 1876 to Present," studied how the use of relief pitchers has changed over the last 100-plus years.

While the rules governing pitching have remained constant, relief pitching has risen dramatically - just 5 percent of all games featured a reliever in 1900; today's game sees a reliever nearly 90 percent of the time.

The lore of the game, however, was a very small part of Kaplan's project. The student spent the summer researching the Los Angeles Dodgers and invented two new statistics for relief pitchers - potential ERA and worst-case era. Potential ERA is when none of the runners on base when a reliever enters the game score; worst-case ERA is when they all do.

"I wasn't sure how much of a difference it would be," Kaplan said, "but for the average relief pitcher, the difference was 100 percent - 2.10 to 4.20. In one case, it was 600 percent (that was Ray Searage, who had an actual ERA of 3.54, a worst-case ERA of 10.85, a potential ERA of 1.51. Luckily for Searage, the pitchers following him to the mound did a good job).

"I did the same thing for the Orioles last summer, and it held up."

KAPLAN'S MOST popular stat, his personal favorite, though, is relievers effectiveness (RE). As he explains:

"One of the main jobs of a reliever is to come in with men on base and get out of the inning with no runs. Under the present system, none of the runs are charged to him, although it's his main job. At the present, no real statistic measures this. So I invented one.

"Relievers effectiveness works like this: For every situation with runners on base, there is an expected number of runs that should score, based on statistics from the thousands of maor-league games played over the last 100 years. For instance, runner on first base, no outs, .783 runs; bases loaded, one out, 1.546 runs.

"With inherited runners, people might say, 'Oh, he allows half of his inherited runners to score,' but for me, that doesn't cut it. What I did, I scaled every situation according to where the runners were and how many outs. All I did was, and it's a fairly simple formula, the number of inherited runners the relief pitcher allowed to score divided by the number that were expected to score.

"An example: Bases loaded, one out, 1.546 expected, he gives up one. One divided by 1.546 gives an RE of .647. Less than 1.0 is good, anything that equals 1.0 is average, greater than 1.0 is not so good. Like an ERA, the higher the number, the worse the performance.

"In mathematical terms, it's called the normalization - for every run that was expected to score, you allow exactly one to score."

At first glance, young Ari may seem like a mad scientist gone berserk after swallowing the Baseball Encyclopedia. But those in the game aren't laughing. Kaplan is in constant contact with John Barr, the former Rider star who is now the assistant general manager for the San Diego Padres, and the Kaplan thesis has led to an interview with Dodgers' general manager Fred Claire.

"It gave me credibility," Kaplan said.


Quite obviously, Ari Kaplan has a rich love for the game of baseball. Interestingly enough, however, it wasn't always that way.

"I grew up not liking it because my brother would interrupt my cartoons to watch a ballgame," he said, laughing.

But in 1986, because of his brother, Ari became a Mets fan. That magical year for the men from Flushing Meadow made Kaplan not just a fan of the game, but one immersed in the statistical end of the spectrum.

When choosing a college, Kaplan knew the money saved from his six-year route as a Times newspaper carrier wouldn't be enough for an education. So, in deciding between MIT, Stanford and Cal Tech, he chose Tech for three major reasons.

"It was in southern California; my brother went there; and the finiancial aid really helped me a lot" he said. "Cal Tech gets about a billion dollars from the government a year, which is more than they send to Poland."

And Cal Tech got Ari Kaplan, who just may redefine the way we look at the game of baseball.

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