Mound Visit: Living and dying on the edge

STATE COLLEGE, Pa. — A minor-league pitching coach from another organization I used to cover once shared with me a tidbit that has stayed with me ever since: "The battle between a pitcher and hitter is usually won or lost on the edges. Unless the [expletive deleted] umpire gets involved."

If his words ring true, then the Pirates' hitters are losing more than their fair share of battles.

First let's answer the obvious question: What the heck do we mean by the edges?

The simple answer is the fringes of the strike zone, in all directions. Statcast has expressed the idea of these nebulous regions in various, iterating ways throughout the past few seasons, including the current expanded detail:

A history of Statcast's zone visualization over the past three seasons.

Through all of these iterations, the numbering has remained consistent right up until version 3, which is the current model. Edges had previously been defined as zones 11 through 19, until the latest map added waste pitches.

Some might call this information overload. To rebut that criticism, one would point to the wealth of data this opens up. Perhaps the presence of an expanded look at all areas can tell us how Chris Archer's slider plays if it lands on these edges, or if Trevor Williams' fastball simply flies in the face of conventional wisdom, gaining effectiveness when his control allows him to dot those same lines. (Hint: It does.)

From this humble perch, there is no such thing as too much data. Yet, certainly not all data is created equally. Newfound information is only as useful as its application. Luckily for us, we can use these "new" areas of the strike zone to explain away why Pirates hitters have had such a tough go of things in 2019.

wRC+, or weighted runs created-plus, aims to serve as an all-in-one metric for gauging run production. 100 is considered league average. Overall, regardless of zone, location and count, the Pirates currently carry a scarlet-letter like 79 as a team. That's 25th among the 30 MLB clubs. If a roll-up metric isn't your style, then I'll be happy to point you towards more widely accepted fare such as Runs Per Game (3.47, 27th), batting average (.234, 23rd) or OPS (.669, 27th), with all metrics here coming prior to the team splurging for 5 runs yesterday -- though it took 13 innings to get there.

We can cut the numbers several dozen ways, but we don't really have to. We know that the Pirates are not great at run production. Despite Josh Bell's heroics, Bryan Reynolds' surprising start at the dish and Melky Cabrera's overall solid play, the PBC simply cannot scratch across enough runs to support their intriguing pitching staff.

With every great deficit comes great opportunity. No, it was not Spider-Man with that quote....it actually is not a famous quote at all, that I know of. But, it fits. Here's a better one, from Andy Dufresne from The Shawshank Redemption:

"I guess it comes down to a simple choice, really. Get busy living or get busy dying."

The Pirates' hitters have been dying on the edges, and they would be keen to heed Andy's words.

The Pirates' hitters carry the worst xwOBA in baseball on the edges, or "shadow" zones if you prefer.  Among the 10 current Pirates hitters on the 25-man roster with at least 30 PAs, Reynolds has seen the most pitches on the edges by volume at 46.7 percent. The rookie also has the distinction of carrying the highest xwOBA of that same group at .315. We don't have to go very far to see an example of his ability to make good judgment on a borderline pitch:

The same is true for Bell, who has three of his home runs from pitches on the edge, and an other-worldly slugging percentage of .630 on those same pitches. Starling Marte pounced on a meatball from Oakland closer Fernando Rodney yesterday for a game-winning three-run homer, but prior to that he had a more patient approach elsewhere, with a 14.9 whiff rate on the iffy ones.

That's the good. But, the bad.....oh my word, is it bad. Here's a full look at the club's xwOBA on the edges, with pitchers de-selected:

xwOBA on pitches on the edges of the zone

Together, Jung Ho Kang and Francisco Cervelli have served as dual fulcrums for this Pirates offense, and both have displayed horrible judgment on the edges, fueling their low figures, with Kang sporting a 38.6 percent whiff rate there and Cervelli at 31 percent. To be fair, we should also point out that currently-injured Corey Dickerson would easily lap the field with a 42.1 percent clip. Colin Moran and Gregory Polanco add to the misery with 29.8 and 29.4 percent marks, respectively.  Here's the full team-look on swing and miss rates for pitches on the edge:

Individual Pirates swing and miss rates on edge pitches

You may have noticed that one Bucs hitter is in what I would call the "sweet spot" in both charts, and that's Adam Frazier. Frazier sees the most pitches on the edge by raw number -- 210 -- yet has maintained what one would call a reasonable swing and miss rate against these pitches. One clear-cut item of note drives this: Frazier does not miss on edge fastballs. He carries the second lowest whiff rate on the club on these pitches, at 10.3 percent. Melky Cabrera actually leads the clubhouse with 7.5 percent, albeit with 59 fewer pitches to offer at.

Here's where it gets philosophical. Is it more desirable for a hitter to offer at these pitches, or simply work to get a better one to hit? The umpires -- as they usually do -- offer no help, as the split between called balls and strikes has been pretty even to date. 23.4 percent have been called for strikes while 24.5 percent have landed for balls. Framing plays a part here, to be sure, but overall the difference between a ball and a strike seems to be minimal on the macro scale.

Speaking of the macro scale, it has been rather alarming to see that Pirates hitters have had the most trouble on the edges with fastballs. To wit, of all the pitches they see on the edges, the Pirates see the third most fastballs at 64.8 percent. And it's not as if they are particularly hard to pick up.

Team swing and miss on edge fastballs by spin rate

A fastball with a lower spin rate will act like a hitter thinks it is supposed to: by eventually sinking a bit -- yes, even if it is not a sinker. High-spin fastballs don't sink as quickly, sometimes giving the impression that they are even rising. Overall, Pirates hitters have seen fastballs on the edges with an average spin below the league-wide mean of 2284 rpm.

So, let's review. Pirates hitters are bad on edges of the zone. They also swing and miss on fastballs there that are easier to track.

That's not a great combo.

The hitters that are struggling -- the Cervellis and Polancos of the club -- would be wise to mimic what Frazier and Bell are doing. Of Frazier's edge pitches seen in two-strike counts -- which should be considered the prime time for an edge pitch as the league throws pitches on the edges at a 38.1 percent clip in two-strike counts -- he fouls off 38.6 percent of them. Bell is right behind him with a flat 25 percent mark. They live to fight another day. And that fight often works out in their favor. On pitches immediately following edge fouls, both have an xwOBA of at least .320 or more, with Frazier clocking at .321 and Bell at .356.

It might seem micro on the surface, but Pittsburgh's performance from their hitters on the edge can serve as a substantial factor in the macro of their poor run production thus far.