In 2015, Chris Rusin made 22 starts for the Colorado Rockies in what was a lost season for the ballclub. They finished in last place for the third time in four seasons, and their attendance dropped to its lowest mark in eight seasons. The club possessed a promising cache of prospects. Regardless, one couldn’t be blamed for feeling pessimistic about the Rockies’ future.

Fast forward to today, and Rusin is still with the team. Instead of working in a starting capacity, though, he’s been moved to the bullpen. And rather than occupying a large role in Colorado’s rotation, he’s not even a sure thing to serve as the club’s sixth or seventh starter.

This isn’t a product of Rusin’s failings, however. He was actually pretty good last year, recording an 83 xFIP- and 76 ERA- in 84 innings of starting and relief work. Rather, the change in Rusin’s role is emblematic of a new development in the organizaion — namely, that the Rockies suddenly have a great deal of pitching depth, both in the rotation and the bullpen.

Let’s start with the most recent starting pitcher to make his major-league debut for the Rockies, Antonio Senzatela. After showing well in 2015 in his first trip through the California League, Senzatela had a very trying 2016 season. First, he missed time due to a shoulder injury. Then, his mother died from cancer back home in his native Venezuela. At the time, the Rockies used his shoulder injury as cover to let him go home and spend time with his family, which isn’t only an understandable but commendable move by the organization. But for those tasked with determining how Senzatela would stack up as a prospect heading into this season, it certainly created uncertainty, as any season-ending shoulder injury normally would. He’s still not very projectable, but he might have snuck on to the back end of Rockies’ team lists had people known why he really missed the latter portion of the season.

Fast forward to 2017, and Senzatela’s major-league debut was certainly promising. Despite hitting Keon Broxton in the face (Broxton fortunately seems to have come away from the HBP unharmed), he was otherwise brilliant on the day, striking out six batters through five scoreless innings. The result was a Game Score of 66 — and a Game Score v2 of 66 — which is pretty good for a Rockies pitcher making his major-league debut. Take a look:

Now, some of this is damning with faint praise. The Rockies haven’t had a ton of good starting pitchers, and even fewer who turned in good debuts. But it’s better than the alternative, which would have been getting rocked. Senzatela’s outing is tied for third in terms of Game Score, and by itself in sixth place according to Game Score V 2.0. Not too shabby.

Senzatela’s bread and butter is his fastball, and he was able to consistently throw it in the mid-90s or higher — and he finished strong, retiring the last five hitters he faced, and eight of the last nine. More importantly, he was able to hit both outer edges of the strike zone, and the bottom of the strike zone, with that 95-plus mph heat:

Again, we don’t want to get too carried away. This is one start, and there are plenty of pitches here that went far wide of the strike zone. But the biggest clusters are on the outer edges of the zone, and seeing all of these 95-plus mph pitches at least suggests that the shoulder isn’t currently a problem.

This was the best Rockies start from the club’s first four games of the season, but there were encouraging signs from Jon Gray and the two Tylers — Tyler Anderson and Tyler Chatwood — as well. Jeff Sullivan already covered why Gray’s start was encouraging. Watching it during our Opening Day live chat, everyone was very impressed with him through his first four innings. As the other Paul S. noted in the Positional Power Rankings, Gray needs to work on avoiding the big innings. He certainly didn’t do that on Opening Day, but the talent is clearly present.

As it is for Anderson, who struck out eight Brewers hitters. In the early stages of his career, he’s proving to be quite the one-two punch with Gray. To wit:

Most 8+ K Starts, First 20 Career GS, Rockies Player # Jon Gray 5 Tyler Anderson 4 Juan Nicasio 3 Tyler Matzek 3 Jason Jennings 3 SOURCE: Baseball-Reference Play Index

Again, though, the Rockies don’t have a long and storied starting pitching tradition. How do they stack up against their peers?

Not bad. Only 11 pitchers who have debuted since 2015 have struck out eight or more batters in four or more starts in their first 20 career starts. Gray and Anderson are two of them. Obviously, this is a little bit of selective parsing, but it illustrates the sort of potential the Rockies have in these two.

Ground-ball machine Chatwood has also seen an uptick in his strikeouts, recording five of them over six innings in his debut. This trend has been developing since last season. In the first half of 2016, Chatwood struck out just 14.9% of the batters he faced. In the second half, though, he struck out 21.3%. In a promising development, he still generated the same high percentage of ground balls — 57.8% in the first half and 56.3% in the second half. If he can keep inducing ground balls at that sort rate and also maintain his strikeout rates from the latter half of 2016, there will be many fewer chances for hitters to do real damage against him.

Right there, you’d already be a little impressed with the Rockies’ rotation depth. But they have yet another impressive young starting pitcher making his major-league debut today in Kyle Freeland (who just missed Eric Longenhagen’s top 100 prospects list), and they still have top prospects German Marquez (No. 52 on Eric’s list, on the major-league club as a long reliever) and Jeff Hoffman (No. 47 on Eric’s list, at Triple-A) at the ready should they need/when they need additional starting pitchers. The aforementioned Rusin also finds himself in this group, along with Harrison Musgrave (Triple-A). It’s the sort of solid, projectable starting pitching depth from which the Rockies have rarely — if ever — benefited. (And we still haven’t mentioned Chad Bettis, who is a solid two-win starter and is aiming to beat his cancer by the end of the season, if not sooner. God speed.)

Speaking of debuts, one Rockies pitcher whose debut people have been eagerly awaiting is Greg Holland. As Jeff noted last month, one of the main reasons to be encouraged by the Rockies bullpen is Holland’s spring training performance, where he looked like his old self. And he certainly has looked like himself in his first three outings. First and foremost, there’s the fact that Holland has been able to pitch in three of the first four days of the regular season. Certainly few would have expected that turn of events. But he hasn’t just pitched, he’s pitched well.

Don’t just take my word for it, though. Feast your eyes, if you will, upon the slider he threw to strike out Brewers catcher Jett Bandy yesterday afternoon.

Tell me — exactly what are you supposed to do with that pitch? A slider like that on the black? All you can do is what Bandy did — take it and hope the umpire doesn’t call it a strike. Holland threw four pitches to the Milwaukee catcher, all sliders, and Bandy essentially had no chance.

But what of his fastball, you might be wondering? Well, let’s go to the very next pitch:

This fastball came in nice and hot — and to a much tougher hitter in Ryan Braun. Looking at Holland’s early fastball velocities and doing a little math to account for the velocity spikes (thanks Andrew Perpetua!), Holland’s velocity seems a touch lower than in his heyday, but playable nonetheless. To recap, these pitches demonstrate that Holland, pitching for the third time in four days, was able to use his two primary weapons while protecting a one-run lead. If that isn’t an encouraging sign, nothing is. If he keeps it up all season, the Rockies will end up with one of the best bargains of this past offseason. And it’s not just Holland. New acquisition Mike Dunn has also pitched three times without allowing a run. The same is true for Carlos Estevez.

Some caveats undoubtedly apply here. The standard “it’s only four games” clause is obviously one of them. In addition, the Rockies will have to face better teams than the Brewers. But the team wakes up today with the fifth-best pitching WAR in baseball, and the third-best xFIP-. There’s promise in all five of their starting pitchers, as well as the two top-100 prospects waiting in the wings. They have a legitimately exciting closer, and a cadre of solid relievers. Many of their young pitchers will be prone to big mistakes from time to time — such is the nature of youth — but the Rockies pitching staff hasn’t looked this good in a very long time.

UPDATE 4/8/17:

Kyle Freeland also had a stellar debut yesterday. Combined with Senzatela’s debut, you’d be hard pressed to find two better consecutive pitching days in Rockies history. In honor of that, I re-did the MLB debuts table:

Best Major-League Debuts by GSc/GSv2, Rockies Starters Player Date Tm Opp IP GSc Gsv2 Mark Brownson 7/21/1998 COL HOU 9.0 85 91 Jason Jennings 8/23/2001 COL NYM 9.0 81 84 Tyler Matzek 6/11/2014 COL ATL 7.0 66 73 Tyler Anderson 6/12/2016 COL SDP 6.1 63 69 Juan Acevedo 4/30/1995 COL HOU 5.0 66 68 Antonio Senzatela 4/6/2017 COL MIL 5.0 66 66 Juan Nicasio 5/28/2011 COL STL 7.0 63 65 Christian Friedrich 5/9/2012 COL SDP 6.0 62 65 Jamey Wright 7/3/1996 COL SFG 6.0 62 65 Kyle Freeland 4/7/2017 COL LAD 6.0 67 64 Drew Pomeranz 9/11/2011 COL CIN 5.0 63 64

By original Game Score, Freeland had the third-best Rockies MLB debut, and by GSv2, he tied for 10th best. Holding a loaded Dodgers lineup (even without Corey Seager) to one run at Coors Field is quite the debut.