Jake Arrieta put the finishing touch on a historic second half of his MLB season with six scoreless innings Friday night.

We take a look at what he was able to do and how low his ERA dropped.

Unstoppable since August

Jake Arrieta has a 0.41 ERA in 12 starts since the start of August. From ELIAS: That's by far the lowest ERA from August on in a season since earned runs became official in 1913 (minimum 10 starts).

Arrieta's 236 strikeouts were a big part to the Chicago Cubs setting a new record for most strikeouts in a single season by National League team's pitchers, breaking the 2003 Cubs record of 1,404 strikeouts. Including their win against the Brewers Friday, Cubs pitchers have struck out 1,414 batters.

Quality all season

From ELIAS: Arrieta has now thrown 20 consecutive quality starts, the longest streak to end a season since earned runs became official in 1913.

He bests teammate Jon Lester, who has the second-longest such streak at 19 games (2014). Arrieta also beat out Greg Maddux, who had 17 such starts in 1997, and Tom Seaver (16).

How Arrieta dominated since Aug. 1

In four of his 12 starts, including Friday, he didn’t allow a hard-hit ball. He allowed 16 hard-hit balls total over his final 12 starts, an average of fewer than 1.5 per game. On balls hit into play against him, 16 were hard-hit while 132 were softly hit.

He hit as many home runs as he allowed (one). The same is true dating back to his June 21 start against the Twins (two HR allowed, two hit). The only HR in those last 12 starts against him came off the bat of Aaron Altherr of the Phillies.

He allowed eight extra-base hits, the same number of double plays he induced.

On pitches thrown in the lower half of the zone, Arrieta allowed a .097 average, struck out 32.7 percent of the batters he faced, and walked only 3.5 percent.

The highest batting average he has allowed with any of his pitches was .168 with his slider.

Arrieta allowed a .143 batting average and .199 slugging percentage in at-bats to end in a breaking ball.