This is a long one. I appreciate your patience in advance.

Mike Podhorzer, I and sporadic others have — but primarily Mike has — carried the torch on developing ‘expected’ metrics, such as xBABIP (expected batting average on balls in play), xHR/FB (expected home run-to-fly ball ratio) and xK% (expected strikeout rate), all and the rest of which can be found here. For the uninitiated, these xMetrics help describe how a hitter or pitcher should have performed based on various measurements of the events that unfolded and typically are more predictive of future performance than the original metric. They’re not perfect, but, like other advanced metrics, they give us a better understanding of player performance and ability.

Each metric — xHR/FB, xK%, etc. — has formulas for both hitters and pitchers, with the hitter metrics typically having stronger correlations than those for pitchers. Unfortunately, pitcher xBABIP has always eluded us. It’s inappropriate to repurpose hitter xBABIP for pitchers, but it’s because the model coefficients (weights) would be different, not because the theory underpinning the model is flawed.

That’s the problem, though: hard hits, line drives, infield fly balls — these all should affect a pitcher’s BABIP allowed. Our intuition begs it to be true. Yet there’s a resounding lack of evidence that suggest otherwise. The correlation between BABIP and hard-hit rate (Hard%), line drive rate (LD%) and infield fly ball rate (IFFB%), among others, borders on nonexistent:

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Here is my latest starting pitcher rankings update! Keep in mind that this is a narrower focus than just “rest of season” as I’ll be updating these again in mid-to-late August for the stretch run. Pitching is just too volatile to have confidence in a single ranking set for more than 4-6 weeks at a time. The tiers are what’s important.

I’ll reiterate again that the Must-Starts aren’t automatically the best pitchers, but rather the guys that you can’t sit with any confidence (they don’t have a platoon split or home-road split and their track record speaks more than the first three months of this season. Please leave your questions and comments below!

Previous Updates:

• March
• May
• June

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At the midway point of the season, it’s always interesting to see how teams are utilizing their pitching staffs. I’ve been examining workloads through the metric I created, called Fatigue Units. This metric accounts for days between appearances, stress during pitching, and time between pitches – you can read more about it here. TLDR; Fatigue Units appear to be a more accurate indicator of “overworked” pitchers than pitches, or innings pitched.

To start off – what does the midway point indicate about a pitcher’s workload? It doesn’t necessarily indicate what the workload will be by season’s end, but it does say that the pitcher has worked hard in the first half. It definitely says that the team has trusted that pitcher, and, that pitcher is very good. Here’s what the halfway point workloads looked like in 2016.

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Since 2013, I have polled you dashingly attractive readers on which group of pitchers you think will post the better aggregate ERA post all-star break. The two groups were determined based on ERA-SIERA disparity, pitting the underperformers versus the overperformers during the pre-all-star break period.

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About a month ago, I started searching for the league’s underthrown pitches. Pitches that despite inducing elite swing-and-miss, ground ball, and pop-up rates, are thrown with scarcity relative to other inferior offerings. It was as an enlightening a topic to research, as it dealt with untapped potential, as it was a fun series to write. Though to be honest, there wasn’t a whole lot of actionable fantasy advice to be gleamed. But in the process of writing those pieces, I had to grade each pitch. And arsenal scores, a subject of interest to the RotoGraphs community over the years, were just a stone’s throw from away from the groundwork I’d already laid.
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Sean Newcomb finally had his first bad start of the season and unsurprisingly it came against the Houston Astros. They are third in wOBA against lefties at .347 and also have the third-lowest strikeout rate at 17%, a tough combo for the 24-year old rookie. Newcomb has actually shown a reverse platoon this year so six of the eight batters coming from the right side wasn’t necessarily a warning sign. Being Astros was the warning sign, let’s be real.

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On Thursday for my American League starting pitching slot, I used my expected strikeout rate metric to determine which starters have the most strikeout rate upside given the components of the equation (strike percentage, along with swinging, looking, and foul strike rates). Today, I’ll look at the starters with strikeout rate downside hinted at by xK%, but expand my group of pitchers to both leagues.

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Today, I’ve got Quick Looks on Newcomb, Gonzales, and Gossett. Let’s start with the young lefty in Atlanta, one of the top pitching prospects in the game.

Sean Newcomb

For Newcomb, I watched his June 21st start against the Giants.

• He’s on the extreme first side of the pitching rubber and throws from a low 3/4 arm slot. This combination will make it tough for left-handed hitters to square him up but right-handed hitters should have a good view of the ball. This idea has not been born out yet, with lefties putting up a .400 BABIP against him.

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The Dodgers Julio Urias is done for the year, and probably most of next season, with a torn Anterior Capsule – a devastating shoulder injury. The anterior capsule is a combination of ligaments which provide stability to the shoulder. Have you ever heard someone state that they had “a frozen shoulder”? Well, frozen shoulders (or, adhesive capsulitis), is impingement of that same capsule, and it results in huge range of motion loss, and incredible discomfort. You can imagine how damage to that structure would be catastrophic to a pitcher.

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Over the last several weeks, I’ve scoured Baseball Prospectus’ PitchF/x leaderboards for the league’s underthrown pitches. We’ve covered two different pitch types each week starting with four-seam fastballs and sinkers in the first installment, cutters and curves in the second, and sliders and changeups last week. This week, we put it all together. Now that we’ve identified the most underthrown pitches, who should consider overhauling his entire pitch mix to make the most of his electric stuff?

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