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Pierce Johnson has given the Atlanta Braves exactly what they needed

Johnson has had success so far as a Brave. Let’s dissect why.

MLB: Milwaukee Brewers at Atlanta Braves
Pierce Johnson has been on fire as a Brave
Brett Davis-USA TODAY Sports

Small sample sizes can be deceiving, but the small sample sizes of the deadline acquisitions the Atlanta Braves made have looked great so far.

Nicky Lopez has taken full advantage of the two games he has started at the plate, going seven for ten with a double and a home run.

Ozzie Albies is now on the IL, and Vaughn Grissom has been brought up, but still Lopez stepping up as a reliable utility player will go a long way in treading water until Albies returns.

Nicky Lopez stepping has been a fun development, but one that is arguably even more impressive is what we have seen from Pierce Johnson. At the time of this writing, he has gone unscathed in the earned run department since joining the Braves. Over eight appearances and 7.1 IP, he has a 0.00 ERA, 1.50 FIP, eleven strikeouts to three walks, and a slash line against him of .185/.267/.259.

This is a far cry from the 6.00 ERA, 4.55 FIP, and .292/.385/.491 he had this season before being traded to the Braves this season.

We saw some indication that Johnson was trending in the right direction just looking his surface numbers when he was traded. In his twelve appearances prior to being traded he had an ERA of .327 and FIP of 3.09, and nine of those appearances were at home (Coors Field). Hitters were still getting on base hitting .289 and having an OBP of .385, but his slugging against of .356 was much lower than his season total of .491 up to that point.

So, what has changed since Johnson joined the Braves?

First Johnson’s batting average of balls in play (BABIP) against him was insanely high. He had a .412 BABIP against. Even with the league average being up about .009 points from last year due to the limited shift (presumably), a .412 is well above the league average of .305. He was always going to eventually have better results.

Now, he was not getting lucky or unlucky in terms of strand rate. His 70.7 percent through July 23rd was right around league average according to Fangraphs. So, we can gather that strand rate did not factor into a high ERA prior to the trade. However, since he has been traded, his strand rate has been a very high 90.0 percent, pointing to substantial luck in that department (albeit, again, in a very small sample).

So, let’s look and see if there are any other variables that have had an impact.

Just by looking at his xwOBA on all pitches, the month of August he has seen a .288, which is well below his .333 in July, .339 in June, and .361 in May. Remember xwOBA is weighted, so simply moving away from Coors is not the only reason why we have seen a drop.

xwOBA by month

Now, if we look at his pitch type, we can see that his curveball usage has gone way up. In the month of August he has used his curve 73.1 percent of the time, as opposed to no other month going over 57.3 percent. With it being a small sample size, we will most likely see this usage drop, but hitters are struggling against the pitch with a an xBA of .152 and xSLG of .193.

Pitch type by month

A large reason for this is that hitters have not been able to hit his curve hard as of late. In the Month of August, hitters are struggling to a hard hit rate of 22.2 percent of the time. In July, they were hitting his curve hard 69.2 percent of the time, and in June 53.8 percent of the time.

Interestingly, hitters are not swinging and missing more on his curve, whether in the zone or out of the zone, so it is not as if their xwOBA is down due to whiffing on the pitch. Johnson’s in zone percentage with his curve is right on par with the rest of the season as well.

His groundball rate is up though. Hitters are hitting his curve into a groundball at a 55.6 percent clip. His second highest month in terms of his curve inducing grounders was in July in which it was only 38.5 percent of the time.

The biggest change seems to be that his vertical movement on his curve has significantly reduced. Every single month his curve has moved vertically less and less. At the start of the year (April) his curve was moving 2.42 ft. Now, in the month of August, it is down to 1.62. In other words, he is tightening up his curve. Interestingly, it seems to be working. His velocity is staying about the same, and his horizontal movement is about the same as it was in June.

Vertical movement change by month

Remember how it was stated earlier that in his previous twelve appearances before the trade he was seeing success? Well, this was right around the time his horizontal movement on his curve spiked from 0.18 ft in June to 0.40 ft in July. The Horizontal break more than doubled and stayed there in August (0.33 ft).

Horizontal movement by month

In summary

Johnson was already unlucky before he joined the Braves due to his high BABIP, so we knew we would see some improvement. However, we have seen more than just a regression to the mean.

Johnson has figured out his curve is his best pitch and has honed in on making it better. His movement has drastically changed to where is moves much more horizontally and less vertically. This has appeared to allow him to induce quite a few more groundballs and has reduced the hard hit rate against the pitch drastically.

Not only has his curve become much better, he is pitching it far more often as well, resulting in better results. He won’t be able to maintain a 90.0 percent strand rate, but based on what we have seen since he has been a Brave, we should continue to see success.

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