Jake Arrieta has had a great 2015 season, but what he just did in August was almost otherworldly. For the month, the Cubs ace was 6-0 and allowed only 19 hits and 2 earned runs across 6 starts that spanned 42.1 innings. Add in 10 runs, 2 errors, and 2 hit batter and you’ve got a total of 33 baserunners allowed; that’s only 5.5 runner per game. For an entire month. Arrieta’s August ERA was a miserly 0.43, his WHIP a microscopic 0.69, and his batting average against an anemic .129.
So how did he do it? Well, the one-grip multi-slider has become one of the most feared pitches in baseball, but Arrieta has a few other arrows in the quiver as well. It’s almost unfair to have a guy out there throwing a live fastball at 95 mph, then lofting a curve at 80 mph, and finishing everything off with slider that lives in the low-90’s. The combination of movement and velocity changes have been keeping hitters off balance for two seasons now, but never has that been more evident than in the last month.
Sunday’s no-hitter was the piece de resistance, but it wasn’t some kind of isolated incident. Rather, it felt more like an inevitability, a planting of Arrieta’s flag at the peak of national consciousness. Or perhaps it’s more fitting to say he left his mark on the Sea of Tranquility, as the reserved pitcher seemed totally unmoved by the magnitude of the moment as he achieved history at Chavez Ravine.
The movement Arrieta is able to get on that power slider/cutter is sexy. The Grizzly Adams beard on his face is sexy. The butt he’s achieved through fiendish devotion to his fitness is really sexy. But talking about location and results isn’t all that sexy. Thing is though, that’s the kind of stuff that shows out in the long run. I mean, a 100 mph heater is pretty cool…until you pipe it a few too many times and get drummed out of the league.
To that end, it should be no surprise that Arrieta’s hot stretch has been underpinned by a trend toward more and more ground balls. Line drives are most likely to result in hits and fly balls can leave the yard, but grounders are going to find gloves more regularly. Take a look at the heat maps below representing Arrieta’s percentages of grounders allowed per balls in play over the first four months of the season and then in August and we’ll discuss in a bit.
There is a bit of a problem, of course, in dealing with a small sample, but part of the reason for that is the fact that Arrieta hasn’t allowed much contact at all over the last month. Just look at the stark differences in these two charts, particularly how Arrieta is keeping the ball down. Even when guys are putting the bat on the ball on pitches over the plate, they’re not doing anything with them.
While Arrieta had been inducing ground balls at a very respectable 51.7% rate through the end of July, that total has jumped to 61% in August. As you might imagine, an increase in one area means a decrease in others, which is exactly the case when it comes to flies and line drives. So let’s take a look at those types of batted balls; same time periods, same stark differences in results.
Above, with the grounders, we saw how the map went from a mish-mash of violet and indigo with blue and red accents to a bright crimson foundation with a couple reddish spires. With the fly balls and line drives, however, the maps have become azure wastelands, each with but a single scarlet island floating near the edge. Perhaps the line drive map is more of a purple archipelago, but it doesn’t appear to offer much hope to those who find themselves stranded on any of its unforgiving shores.
When I wrote about the no-no in the wee hours of Monday morning, I referred to Arrieta’s performance as a song of ice and fire, which I borrowed from the series of books by George R.R. Martin upon which the Game of Thrones TV series is based. Likewise, the heat maps above are the sum of multiple volumes that weave a story of burgeoning greatness for the Cubs starter.
Like getting lost in a good book, Jake Arrieta seems to have fallen into the mythical phenomenon known colloquially as “the zone,” that inexplicable confluence of skill and good fortune that has swept many an athlete to historic performances. By Arrieta’s admission, he was unable to describe some of the events of his no-hitter and had to turn to fellow starter Dan Haren to tell him what had happened in the last inning.
This spectacular run hasn’t been the result of some fluke, though, as Arrieta has been steadily improving throughout the season. Now he looks to continue his run through the final month of the season. And if he can continue to induce ground balls and baffle batters with that trio of treacherous tosses, there’s no reason the ace can’t continue to pound opponents well into October.