Mariano Rivera’s Road Woes

Mariano Rivera blew his fourth save of the season yesterday, nearly as many as he blew last year (five) and more than he blew in 2008 and 2009 combined (three). All four blown saves have come on the road and three of the four have been one-run leads, the other a two-run lead. Unsurprisingly, Rivera’s home/road splits are pretty drastic this season…

Of course stats like ERA and opponent’s AVG/OBP/SLG don’t tell the whole story. Those are output stats, they just tell us about the results and not what led to them. The process is what is really important, and Rivera’s underlying performance shows us there’s nothing to be concerned about…

The sample size is essentially the same in terms of batters faced, and Mo’s strikeout and walk numbers on the road are for all intents and purposes identical to his career numbers (8.21 K/9 and 1.80 uIBB/9). His ground ball rate is right in line with his rate since 2002 (53.4%), when the data started being recorded. The only significant difference between his home and road performance this year is the number of balls that are dropping in for hits, an astronomically high 43.9% away from Yankee Stadium. That’s almost 18% higher than his career average.

Furthermore, let’s look a little deeper at those four blown saves. Other than the first one against the Blue Jays on April 19th (a legit blown save that featured a double into the gap and some hard-hit singles), they were all of the death by a thousand cuts variety. The ninth inning on April 24th went walk, strikeout, strikeout, bloop single, ground ball past a diving Mark Teixeira into the corner for a double. The tying run scored but the second runner was thrown at the plate by several steps. One hard hit ball, and it was beat into the ground.

The May 18th blown save went ground ball out, single up the middle, single on a ground ball through the right side, sacrifice fly to tie, pop-out to end the inning. And then there was yesterday, which went strikeout, ground ball out, walk, single off the handle of the bat, single on a ground ball through the right side, ground ball through the shortstop’s legs, runner out at the plate. If Mo was giving up rockets all over the field and balls over the fence, I’d be concerned. Right now it’s just a case of sample size and dumb luck with ground balls having eyes more than anything.

It’s worth noting that Rivera’s trademark cutter is completely unchanged this year. The velocity is the same as it’s been over the last few seasons, comfortably in the low-90’s, and the pitch is still getting three-plus inches of horizontal break and just north of five inches of vertical “drop.” Batters are swinging and missing at Mo’s cutter 7.8% of the time this season after whiffing at it 8.0% of the time over the last two years. There are no red flags here, so don’t bother worrying.