XM MLB Chat: Mariano Rivera is better defined by ERA+ and WHIP, not the Save stat-Barbarisi

9/14/11, "Rivera's Greatness Not Limited to Saves," Wall St. Journal, Daniel Barbarisi

"Is He the Best Modern Pitcher? Stats Make a Compelling Case"

"The statistic that is most often associated with Mariano Rivera is the save, and this week, as he looks to claim his 600th and takes aim at the all-time record of 602, he'll be celebrated for all the saves he's earned. Saves tell a story, but a limited one. Created in the 1960s, it is earned when a pitcher throws an inning to finish a game with no more than a three-run lead; finishes a game with the tying run on base or on deck; or when a pitcher throws three innings to finish a game.

Some saves are meaningful, others are largely inconsequential, like when Texas's Wes Littleton "saved" a 30-3 rout of the Baltimore Orioles in 2007. Rivera has had many of both over his 17-year career.

But even all 600 don't begin to catalogue the greatness of Mariano Rivera. When Derek Jeter notched his 3,000th hit earlier this year, the fanfare was appropriate—

the hit is the perfect stat to define Jeter.

For Rivera, the save is not. For that, it takes other numbers to truly do justice to this unique pitcher—and to assess his rank among the greatest of all time.

First among these is earned run average. Relievers often have deceptive ERAs. When they enter in the middle of an inning and give up runs, those are assigned to another pitcher. In the same way, they are often bailed out by other pitchers.

But ERA is the yardstick for measuring pitchers, and no one in the game today has a better career ERA than Rivera's 2.22. In fact, no one in the last 90 years has an ERA even close to Rivera's. Rivera is 13th all-time in ERA, and none of the 12 pitchers ahead of him pitched after 1927. They come from a different time, when the ball was literally constructed differently. In the post-dead ball game, the next best pitcher by ERA is Hoyt Wilhelm, who

retired with a 2.52 career ERA in 1972.

There are ways, however, to account for the differences across generations.

Partially to account for the disparity between the modern era and the dead-ball game, statisticians created a formula, ERA+, to measure how a pitcher fares across different time periods. A low ERA in a period when fewer runs were scored is worth less than a low ERA during the steroid years, for instance,

when offense dominated and ERAs were high.

An ERA+ of 100 is considered average. Anything above that is good. Cy Young, for instance, has an ERA+ of 138.

Tom Seaver has a 128.

However, no one is better than Rivera, who has an ERA+ of 204. No one else is even close. The next best figure, Pedro Martinez' 154, comes from another dominant pitcher in an offensive era. But no one can duplicate Rivera's astounding success.

It's generally argued that starters are more valuable than relievers because they log more innings, and must go through a lineup multiple times. That rings true to manager Joe Girardi, but he still sticks to the statement that Rivera is the best he's ever caught—and this is for a man who caught Roger Clemens, among others.

Another number is even more impressive.

The primary job of a pitcher is to keep runners off base. The fewer walks and hits they allow, the better. There's no simpler way to gauge this than by measuring walks and hits per innings pitched. And that number reflects Rivera's true dominance. He is third all-time in WHIP, allowing exactly one combined hit and walk per inning. There are only two pitchers better—

Hall of Fame dead ballers Addie Joss and Ed Walsh.

There are more. His strikeout-to-walk ratio is fifth best in baseball history. He's allowed fewer home runs per nine innings (0.48) than any active pitcher. Heck, his fielding percentage (.983) is ninth-best in history for a pitcher. ...

Saves will be what he is remembered for. But it's all the other numbers that make him