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Jake Arrieta's amazing August

Jake Arrieta threw a no-hitter in his last August start, but that game was just icing on the cake.

Caylor Arnold-USA TODAY Sports

Remember at the start of the year when we had all these questions about whether or not the Chicago Cubs would compete this year? After acquiring Jon Lester, Miguel Montero, Dexter Fowler, and some other notable talent to complement their upcoming young superstars, people wondered if the Cubbies would be able to make an immediate run at the playoffs in 2015. Were the likes of Kris Bryant, Addison Russell, Kyle Schwarber and Jorge Soler ready to play at the highest level, or would they require some time to get acclimated?

Here we are in September, one month away from the start of the playoffs and at this point, it seems the answer is clear. The Cubs currently have a healthy grip on the second National League wildcard spot—and have for about the past month. As a matter of fact, if they were in any other non-Central division, the Cubbies would be in first place.

Not only were Bryant, Russell, and Schwarber ready and able to help immediately, but the Cubs have also gotten big contributions from veteran-type guys not listed above. Guys like Anthony Rizzo, Jason Hammel, and Chris Coghlan have been instrumental in Chicago’s quest to reach the playoffs for the first time since 2008.

Obviously restricting Rizzo to just a sentence in talking about how much he has meant to the Cubs this year is doing him an injustice, as he has been/done everything they could’ve asked of him. Stat-wise, Rizzo (4.6) trails only Kris Bryant (5.1) for the team lead in fWAR. Non-stat-wise Rizzo, has been the fearless clubhouse leader of the north-siders.

This is the part where I cue up the Five Finger Death Punch cover of ‘Bad Company’. This is also the part where Jake Arrieta kicks open the door, rips his sunglasses off, and chucks them at a nearby wall. A grandiose—albeit wasteful—entrance for an elite pitcher (and one who, apparently, is Bad Company). I guess that’s what you’re able to do once you no-hit the Los Angeles Dodgers—did Mike Fiers set precedent with that?

So that is how Jake Arrieta enters this conversation, but he plays baseball too, right? He does, and he plays it very well. As a matter of fact, leading up to August Arrieta has managed to pitch at a high level and improve as the season progresses:

The Lead Up
March/April 26.2 23.8% 6.7% .236 80.5% .226 .081 2.03 2.54 3.03
May 38.1 27.5% 4.6% .343 64.1% .311 .157 3.99 3.19 2.59
June 33.0 27.7% 6.9% .272 80.8% .262 .117 2.45 2.74 3.10
July 42.2 27.2% 6.8% .257 80.3% .239 .104 1.90 2.22 2.63

Through July 31st, Arrieta owned a more than respectable and all-around impressive 2.62 ERA, 2.66 FIP, and 2.80 xFIP. The 29-year old was also striking batters out at a rate (26.7 percent) just shy of the highest in his career, not to mention inducing a higher ground ball rate than ever before (51.7 percent). Not to mention a .280 BABIP, while low in-general, was right on par with his career average.

Then there is August.

Last week I wrote about Josh Donaldson and the great getting better, this week is the pitcher-version of the same thing. Arrieta was already pitching well, but last month he took it to another level. In fact, with his no-hitter on the second to last day of August he took it to an even higher level as far as national notoriety goes. In a way, it was the perfect ending to a lights out month. Not only that, but the fact that Arrieta allowed only two earned runs across 42.1 innings should lead you to the conclusion that lights out is an accurate descriptor.

Check out the overall stat-line of Arrieta’s August:

Arrieta's Amazing August
August 42.1 27.0% 6.3% .183 87.1% .172 .042 0.43 1.95 2.54 1.72 15.23

Only two pitchers had a better month, according to fWAR, than Arrieta. The San Francisco Giants’ southpaw Madison Bumgarner (2.2) and Dodgers hurler Clayton Kershaw (1.7) would fit the aforementioned description. However, neither produced nearly the amount of groundballs that Arrieta generated. Obviously I’m not saying that they should have, nor am I saying that it would’ve helped them pitch even better than they did, but the point remains.

In Arrieta’s case, however, the near 10 percent increase in ground balls from 51.7 percent pre-August to the 61 percent during August was crucial in the greater success he had. When opponents hit .156 on ground balls against you ( which is tied for fourth lowest among pitchers with at least 50 grounders in play), I assume you'd want nothing more than to welcome more ground balls.

The increase of ground balls is, of course, facilitated by an across the board GB/BIP increase in his main pitches. More specifically, however, it is the result of Arrieta throwing his sinker more often. The same sinker that is a ground ball machine, creating them 57 percent of the time a one is put in play this season. The increased ground balls likely correlate to hitters abysmal ability to hit it for any power what-so-ever, as ground balls generally signify weaker contact—i.e. less power.

For Arrieta, ground balls played a big role in his dominant August—spearheaded specifically by an increased usage of his sinker. Another area of Arrieta’s game that led to this outburst was an ability to create more whiffs inside the strike-zone. Increasing your whiffs as a pitcher is always a good thing, but can surely be only a better thing when increased inside the strike zone. Check out Arrieta’s whiff/swing percentage breakdown by zone this season before August and the same breakdown during August:

Here you can clearly see parts of the strike zone begin to turn red, meaning that they are becoming hot spots for whiff activity. Although August only saw around a two percent overall increase on whiffs inside the strike zone, it is still a sign that hitters even struggled with Arrieta on the strikes he threw.

So an elevated ground ball and whiff total helped Jake Arrieta dig even deeper and find some fantastic stuff that he used to stifle the Pittsburgh Pirates, then the Giants, then the Chicago White Sox, then the Atlanta Braves, then the Giants (again), before finally finishing up with the Dodgers. Over that span, hitters struggled to get anything more than a single or a pass back to the dugout—and more-so the latter.

So is this type of performance sustainable for more than just the month of August?

A .183 BABIP and 87.1 percent LOB% would suggest not, but that doesn’t necessarily mean a September and/or October implosion is inevitable. What it means is that, while Arrieta was remarkably good last month, he also had some help from the BABIP dragons. It is better, though, to look back at his National League pitcher of the month campaign in retrospect. To recognize how truly awesome it was, and how the Cubbie topped it all off with the sixth no-hitter this season.

Going forward, though, the Cubs would love nothing more than for this current version of Jake Arrieta to show up for the impending wildcard match-up against the Pirates. They’d be crazy to give anyone else the nod.

. . .

Shawn Brody is a contributor for Beyond the Box Score as well as a sophomore pitcher at Howard Payne University majoring in Business Management. He has the current misfortune of being a Red Sox fan. If you would like to get a hold of him, please feel free to email him at or follow him on Twitter @ShawnBrody.