What's Wrong with Jose Berrios?

The Minnesota Twins are surging, winners of 7 of their last 10 games. According to FanGraphs, the Twins have a 99% chance of making the playoffs, a near lock, and a 87% chance of taking the AL Central crown. The Twins are powered by their high-octane offense that leads the league in OPS and HRs: .838 and 253 respectively. However, pitching trumps hitting when the calendar flips to October.

The Twins starting pitching is top 5 in FIP- but their ace, Jose Berrios, has been scuffling of late:

Since opening day thru the trade deadline (3/28 - 7/31), Jose Berrios was pitching like an Ace. Berrios tossed 141.2 IP with 133 Ks and 30 BBs to the tune of a 2.80 ERA, 1.10 WHIP and 3.61 FIP. The ERA and FIP disparity of almost a run can be explained by his 1.02 HR/9 which ranked 20th best among 74 qualified starters and significantly lower than this year's MLB average HR/9 at 1.40. He kept his HR/9 low with a 20%/ 42% / 38% Line Drive / Ground Ball / Flyball rate and a whopping 16% IFFB rate, ranked 3rd best only behind Kershaw (18%) and DeGrom (16.5%). His bread & butter pitch, the fastball, saved 15.4 runs above average which ranked 6th best among qualified starters. His fastball generated an overall 12.4 % Whiff rate and a ridiculous 40% last month. This phenomenal period compiled a 77 FIP- for Berrios, ranked 18th best in the league, tied with Clayton Kershaw and Sonny Gray.

This month, Berrios has done a full 180 degree turn. His 8.44 ERA in August ranks 2nd worst only to Jon Lester (8.51, yikes). The 25 year old went from being in the 87th percentile to 1st percentile in ERA, thats crazy.

What caused this absurd change of events? His hard hit rate and flyball rate have both increased by 5%. This has led to his HR/9 skyrocketing to 2.54 with a .394 BABIP, 6th highest among qualified starters. His elite IFFB has dropped to a mediocre 3.3%. Hitters have a 92% contact on pitches thrown anywhere in the strike zone, thats 8th highest among all MLB starters this month compared to an average of 85% during his elite stretch.

Which of Berrios' pitches are hitters able to square up on now? Unfortunately, its his fastball. His fastball has given up 7.2 runs more than average this month alone, ranked 3rd worst among qualified starters this month. Berrios allowed 5 solid contact hits off of his fastball during the first 5 months of the season, he's allowed 4 already in the past 3 weeks. His elite 40% whiff rate in July off fastballs has halved to just 20% this month, with zero whiffs on heaters over the heart of the plate. All of this has compiled a 133 FIP-, ranked 13th worst this month.

How can a Pitcher so dominant over a long period of time become so mediocre so quick? Let's take a look at his fastball heat maps:

Fastballs during first 5 months of the season (left) and August (right)

He's definitely throwing more hittable fastballs, with a higher pitch% to the heart of zone. He's thrown 12% more fastballs right down broadway than during the first 5 months of the season.

But still, its suspicious that hitters are sitting dead red on his fastballs when he's continued to smartly mix in curveballs (28% pitch usage) and changeups (16% pitch usage). He's been able to keep batters off balance and guessing for the first 5 months, what's changed this month?

I delved into his release point for each respective pitch type after seeing this split:

First 5 months (left) and August (right)

Through the first 5 months, his release point between his fastball, curveball, and changeup were all vertically separated by merely an inch. However, his fastball and changeup are vertically separated by nearly 4 inches this month. That is significant. His fastball is being released 4 inches above and 2 inches closer to the rubber than his changeup. This difference allows the hitters to visually distinguish between his changeup and fastball right out of the hand and are thus able to sit on the fastball while laying off his changeups.

A combination of poor pitch location, bad luck, and release point disparities has led to Jose Berrios' struggles. This sport is truly a game of inches and to get back on track, Berrios needs to return to his previous pitch release point mix to keep the batters guessing and off-balance.