It did not look like a terrible pitch. Lets examine in more detail.
Here's a screenshot an instant before contact.
The Fox angle is screwy - it's way to the right of dead center, so that pitch is actually close to the outside corner.
Tim McCarver called the pitch a fastball in real time, but according to Brooks Baseball, it was a split fingered fastball. It was supposed to dive; it didn't. Still, Brooks Baseball classifies the pitch as being the lower, outside third of the zone to Ortiz.
At BrooksBaseball, they classify splitters with changeups and screwballs as "off-speed pitches" in a separate category from breaking balls (sliders and curves).
The following heat map shows where pitchers threw Ortiz off-speed pitches for the 2013 season. Breaking news: they threw Ortiz soft stuff low and away. (Click on all of the heat maps to embiggen and all are taken from the catcher's perspective.)
And the reason? It worked often. This is Ortiz's whiff percentage against such offerings in 2013. He will chase low and away.
And the bad news for the Tigers. When Ortiz made contact against pitches low and away, he could do damage with them. Ortiz slugged over .700 when he made contact with an off-speed pitch in the far low and outside third of the strike zone in 2013.
Now, there are few enough hits in those tables that Sunday night's grand slam skews how dangerous Ortiz is on such pitches low and away.
Here's his career.
Ortiz handles the soft stuff middle-down very well, and still slugs over .500 on balls in contact on off-speed pitcher in the lower outer third.
MetsFor comparison, and for a Mets angle, look at how poorly their two first baseman fared on such pitches in their careers.
Duda can hit offspeed pitches that are centered. However, as soon as a pitcher moves to the outer third or off the corner, Duda is toast.
Davis' profile looks like Duda. He can handle a breaking ball that misses down over the middle of the plate. And as pitchers move away from him, the boxes get bluer and bluer.
Other Left-Handed Sluggers
Lets take a look at some of the leading left-handed power threats in baseball from the last five years.
Prince FielderThe Royal One handles off-speed misses that end middle-down and away-middle and absolutely punishes them, but he slugs under .300 on contact on balls that are both in the bottom third and outer third.
Joey VottoVotto is a plate coverage monster and like Prince abuses off-speed stuff middle-down, away-middle and middle-middle. Even he does not have the coverage to the lower outside corner as Ortiz does, slugging .344 in the box low and away in the strike zone.
Joe MauerJoe Mauer, crushes off-speed pitches up. (Note: this sentence has been edited, as I originally referred to his "hard decline," but really, his last two years have been excellent.) And no, he's not Ortiz on the stuff low and and way.
ConclusionBenoit did not throw a good splitter to Ortiz. It was flat. As Jeff Sullivan explains at Fangraphs this morning, the pitch had five fewer inches of vertical break than Benoit's other splitters in the inning.
However, among left-handed power threats, Ortiz is unusually strong on pitches low and away. He's better than Votto, Mauer, or Fielder on contact low and away. So, he was the right batter, on the right pitch at the right time.
As any Red Sox fan would say, "duh."