If one were to assemble a list of the major-league pitchers whose strengths are most well suited to surviving in Colorado, Kyle Freeland would appear among that collection of names — in particular, because he possesses both a good sinker and strong command. The sinker is important for inducing ground balls, which cause much less damage than balls in the air at Coors, due both to the altitude at which the park rests and the spacious outfield it contains. Command is important not only because mistake pitches are punished more swiftly at Coors, but also because walks tend to amplify the consequences of those mistakes.

Kyle Freeland had a modestly successful rookie season a year ago, getting a lot of ground balls and putting together a 4.57 FIP, perfectly average when factoring in his ballpark. He struggled a little to start the season, but over his last four starts, he’s defied the Coors Field stereotype by abandoning his sinking fastball and pitching up in the zone. So far, it is working.

For comparison, here are Freeland’s stats last season, as well as his starts this season split in half.

Kyle Freeland During Three Periods Period IP K% BB% HR/9 ERA FIP 2017 156.0 15.6% 9.2% 1.0 4.10 4.57 First Four Starts, 2018 20.0 19.1% 10.1% 2.3 5.85 6.05 Last Four Starts, 2018 27.1 25.5% 7.6% 0.0 1.65 2.05

Comparing Freeland’s 2018 numbers to his 2017 line, one finds similar walk and home-run rates, a decreased ground-ball rate, and an increase in strikeouts. On the whole, Freeland seems to have improved as a pitcher since last season. By breaking down 2018 into two four-start clips, however, we find that those improvements are almost entirely a product of his last four starts.

To determine whether Freeland’s recent performance is the result of luck or random variation, we need to go a bit deeper. Freeland hasn’t allowed any homers in his last four starts, which is good but unsustainable. However, even with a more typical home-run rate, the strikeout and walk rates tell us he’s been pitching differently.

Below is Freeland’s pitch mix from three different periods: the 2017 season, his first four starts this year, and his most recent four starts.

Kyle Freeland Pitch Mix Pitch 2017 First Four Starts, 2018 Last Four Starts, 2018 Four-Seam 31.5% 21.5% 46.1% Sinker 33.0% 32.1% 8.0% Cutter 24.9% 29.1% 29.1% Change 6.4% 11.1% 11.1% Slider 4.2% 6.3% 5.7% SOURCE: Brooks Baseball

We can see that Freeland is using his cutter a little bit more this season, consistent across all eight starts. There’s also increased use of the change, a pitch he discussed with David Laurila before the season. Both of those usage rates, while having increased since 2017, have remained the same throughout this year. The big difference comes in the form of increased usage of the four-seam fastball at the expense of the sinker.

While the sinker-throwing pitcher inducing ground balls might seem like the good fit for Colorado, that’s not actually the reality of the situation: the Rockies’ best pitcher, for example, is Jon Gray and he throws a four-seam fastball most of the time. Chad Bettis and German Marquez also feature four-seam fastballs. What’s interesting about those pitchers — as well as Freeland — is that the spin rate on those four-seam fastballs is below average in every case and all those pitchers do a solid job of inducing ground-balls. Only Tyler Anderson has given up a lot of fly balls, and he deploys a sinker a decent amount of the time. Perhaps a low-spin four-seam fastball that has some of the swing-and-miss features of a typical four-seamer and also some ground-ball tendencies of a two-seamer is an ideal fit for Coors. It seems to be working for Freeland, at least.

As a lefty starter, one of Freeland’s main concerns is how to contend with righties. Here’s his strikeout and walk rates by handedness.

Kyle Freeland Platoon Changes Split K% BB% First Four Starts v LHH 31.8% 18.2% Last Four Starts v LHH 56.0% 4.0% First Four Starts v RHH 14.9% 7.5% Last Four Starts v RHH 16.1% 8.6%

Perhaps surprisingly, Freeland’s outcomes against righties actually don’t seem to have changed all that much during his recent run. We’ll get back to that. Where the big swing has occurred is to lefties. We are dealing with a pretty small sample here, so it is tough to be concrete about the changes. The pitch mix hasn’t actually changed all that much, as the table below indicates.

Kyle Freeland Pitching v Lefties Pitch First Four v LHH Last Four v LHH Four-Seam 32.2% 32.7% Sinker 13.8% 8.2% Cutter 50.6% 55.1% Change 0.0% 0.0% Slider 3.5% 4.1% SOURCE: Brooks Baseball

Rather, it’s the location of the pitches that has changed. Consider: this is where his four-seam fastballs went against lefties in the first four starts.

Low and away isn’t a bad place to pitch against lefties, but it does look like he might have left a few in the middle of the plate. Here’s where the location has been the last four games.

Freeland is going higher in the zone and further away from the batter on the fastball. These changes are admittedly slight, and might not hold up, but the bigger change has occurred on the cutter. The story here is perhaps better told through a zone map, from Baseball Savant. Here’s where Freeland was throwing his cutter the first four games of the season.

That’s pretty typical for a cutter/hard slider: down and away from same-handed batters. Notice the zero in the top left. Now, here’s what he’s done in his last four starts.

Getting the pitch up induces more swings. Of the 11 pitches in the top-left quadrant, Freeland got six strikes on five swings: two ground balls, one foul, two whiffs, and a called strike. Even in the lower-left quadrant, Freeland got better results when the ball was higher. Here are those cutters.

There were just two swings and misses in the bottom half of that quadrant with 10 balls. That pitch is more likely to be wasted. With slight elevation, though, we see five of seven swings with one foul and four whiffs. Freeland is experiencing more success by moving up in the zone. It is not as if these pitches aren’t still low, but they are more likely to generate swings if they aren’t near the dirt, like this cutter to Brandon Nimmo

Freeland isn’t likely to keep striking out 14 lefties for every free pass he gives them, but he appears to be over some of the control issues he endured during the first part of the season. His strikeout rate against lefties last season was 27% against just a 5% walk rate. That will work just fine, but there does seem to be some potential for improvement. Against righties, switching to the four-seam fastball might not get as many ground balls as it used to, but it might reduce the number of extra-base hits. Last season, Freeland gave up 17 extra-base hits on the sinker, more than three times as many as the four-seamer despite fairly similar usage. The change in pitch mix the last four games has been huge.

Kyle Freeland Pitching v Righties Pitch First Four v RHH Last Four v RHH Four-Seam 18.20% 50.70% Sinker 37.70% 7.90% Cutter 22.20% 20.30% Change 14.60% 14.80% Slider 7.10% 6.20% SOURCE: Brooks Baseball

The sinker is a nibbling pitch, as seen below to righties in Freeland’s career, per Baseball Savant.

Freeland recently indicated he wants to be more aggressive inside. This is where his four-seamer goes to righties.

Freeland is coming after batters, whether they are right-handed or left-handed. He’s making more aggressive pitches above the knees, even if they aren’t all in the strike zone. He’s got the command to be effective, and it’s been working of late. If he can keep dominating lefties while pitching more competently against righties, he might move from fifth starter to No. 2 pretty quickly.