Digging Deeper – Mariano’s Injury

Rivera gets carried off the field after tearing his ACL in Kansas City May 3rd

Despite Rafael Soriano’s strong performance so far in 2012, Mariano Rivera’s absence has hurt the Yankees in more ways than the surface conveys.

This year, Soriano has thrown to a 2.10 ERA and has beautifully patched up Rivera’s absence. His 42 saves through 152 games have already surpassed Rivera’s average of 40 over the last three seasons. Soriano has blown four saves in 2012, identical to Rivera’s annual average over those same three years.

On May 3rd, Rivera tried to track down a Jayson Nix fly ball during batting practice in Kansas City, but tore his ACL near the warning track at Kauffman Stadium, ending his season and wreaking havoc in New York.

Enter Rafael Soriano – Rays closer from two years ago. Instead of Yankees management pushing 2011’s eighth-inning man David Robertson one inning up the totem pole, Joe Girardi pops Soriano from the seventh inning to the ninth.

As a side note, I thought it was the correct move at the time. From 2009-11, both Soriano and Rivera struck out just over a batter per nine innings, both sported an above average K/BB ratio, and while Rivera’s ERA was better, Soriano’s experience translated into the closer role better than the talented, but young Robertson.

But to say the Yankees have not been hurt by Rivera’s absence is wrong.

This year, the Yankees have thrown to a 3.32 ERA in the seventh inning (source here). By filling Rivera’s gap, Soriano simply borrows from Peter to pay Paul. The seventh inning role is left unfilled by a solid, trustworthy arm and is instead patched together with a hopeful concoction of unproven or young arms (Clay Rapada, David Phelps, Boone Logan, Cody Eppely, etc.)

NUMBER CRUNCHING: Soriano has pitched in 66 games this year. For argument’s sake, let’s say all those games came in “close” ballgames in the seventh inning, the inning he would pitch if Rivera were healthy.

Ignoring the fallacy of the predetermined outcome, let’s say Mariano is himself and Soriano still throws to a 2.10 ERA, allowing all 15 earned runs in the seventh inning. Taking the 3.32 ERA of Yankees seventh-inning pitching in 2012, opponents would score about nine less runs than if Mariano was healthy.

While this ignores many variables and requires multiple assumptions, you can’t ignore the big picture: The Yankees would average more wins, and have a greater chance to win the World Series, if Mariano Rivera was healthy, despite Soriano’s excellent season.

To look at it from a different angle, Rivera has averaged about three wins after replacement over the last three years according to baseball-reference.com. Say average seventh-inning pitchers are replacing Soriano, the Yankees would have a four-game lead over Baltimore with 10 games to play, not one.

In the first year with added emphasis on a division title, a four game lead would allow Girardi to relax and set up his pitching rotation for a likely ALDS appearance.

The game has changed over time. One hundred years ago, starters threw complete games every outing and the bullpen was reserved for starting pitchers that just weren’t good enough.

Slowly, a closer was in demand, then an eighth inning reliever, and in today’s game, a seventh-inning pitcher.

Since 2004, no pitcher has thrown over 255 innings in one season. In 1993, six hurled more than 255 innings. In 1963, six pitchers threw at least 275 innings, three over 300.

For the cherry on top, Will White threw 680 innings in 1879, and all 75 of his starts were complete games.

(For this reason I think Cy Young’s record of 511 wins is the most unbreakable record in sports, but that’s for another day.)

Since 2008, starting pitchers average a tad under six innings per start (141,878.1 innings pitched in 24,010 MLB starts since 2008 averages to 5.92 innings per start), so for a championship team, a seventh-inning man is vital.

With Rivera back in 2013, the Yankees have the best back end of the bullpen on paper. For a perennial offensive juggernaut, a trio of Soriano, Robertson, and Rivera will give the Yankees’ starters the confidence to relax and focus on just six strong innings, while the offense knows a late deficit is always within reach.

As for this season, are the Yankees a championship team without Mariano Rivera? No, but they are capable of winning the World Series. There’s a difference.