Sem Robberse would be considered “a pitcher” by former Blue Jays colour commentator Pat Tabler, and realistically, I’m on board with that description.
Robberse’s backstory deserves its own article, which many people (including myself) have written about it in the past. It also happens that the Dutch-born player is also Blue Jays Nation’s 9th-best prospect.
Let’s start with the criteria. 

Brennan’s criteria:

Instead of writing this out every time I did for the mid-season Top 60, I’ll copy and paste my criteria for how I rank and scout these players.
There are many factors that determine a top prospect. The eye test is the biggest driver in determining a top prospect, but proximity to the majors, ceiling, and floor is also important. Moreover, statistics are another key ingredient, as everything works together to give you numbers.
As for the grades, it’s important to remember that they are relative to the league in which they play. A kid from Dunedin is not going to have a 50-grade hit tool if he were placed in the big leagues. But relative to the league in which he plays, a .300 hitter is eligible to have that grade.
For these prospects, I’ll be reviewing their background, numbers in the minors, pitch mix (if they’re a pitcher), and giving a scouting report (if feasible, rookie league guys are difficult).
Let’s jump in!

Sem Robberse‘s career so far:

The 21-year-old righty was signed from The Netherlands during the 2019 international free agency period.
The “Pitching Dutchman” started his stateside professional career with the Jays rookie league team, posting a 0.87 ERA and 2.06 FIP in 10.1 innings pitched in 2019.
Robberse started the 2021 season with the Low-A Dunedin Blue Jays, where he posted a 3.90 ERA and 3.63 FIP in 57.2 innings pitched. To go along with this, he had a 25.5 K% and an 8.4 BB%, which eventually got him promoted to High-A Vancouver later that season.
With the Canadians, the then 19-year-old posted a 5.23 ERA and 5.20 FIP in 31 innings pitched. His K% dropped to 19.3%, while his BB%% rose to 12%. While the numbers weren’t great, Robberse was very young for the level, so it had to be taken with a grain of salt. That begs the question, how did he do when he repeated the level in 2022?
The then 20-year-old had a 3.12 ERA and 3.85 FIP in 86.2 innings pitched, with a 21.8 K% and a pretty low 6.7%. This was significantly better than his first go at the level, and he earned a promotion to Double-A New Hampshire towards the end of the season.
Unlike in 2021, Robberse had success after his promotion. He posted a 3.65 ERA and a 5.44 FIP in 24.2 innings pitched. He still had a BB% that was a little above average at 9.6%, and his K% dropped to 18.3%. It’s worth noting that in his first four starts, he only had 10 strikeouts, but in his last start, he had 9.

Sem Robberse’s stuff:

Robberse has a five-pitch mix. Two variations of the fastball, which sits 92-95 mph. His best pitchers are his secondaries, with a curveball that sits high-70s, low-80s, and a slider that sits from 84-88 mph. He also has a changeup which is still under development. It sits between 85-89 mph.

Scouting report:

A tall, lean frame with plenty of projection, Robberse has a five-pitcher mix. He has two variations of his fastball, a two-seamer, and a four-seamer, the former has arm side run, which pairs well with his changeup which also has arm side run. His curveball is his best pitch, as it’s relatively hard with good spin. He has a gyro slider which can be thrown for strikes. At points, he can be hit hard when he loses his command, but overall he’s pretty pinpoint with his pitches. Robberse has a mid-starter rotation ceiling, but also a rather high floor.


Fastball: 50
Slider: 55
Curveball: 55
Changeup: 45
Control: 45
Overall: 50

Where he’ll start in 2023:

Robberse is likely to start the 2023 season repeating the Double-A level, similar to how he repeated High-A to start the 2022 season. While it’s not completely necessary to take the next step, a tick-up in Robberse’s velocity could move him from a mid-rotation ceiling, to potentially even higher.
The “Pitching Dutchman” eats innings, has good command, throws strikes, and has great secondary stuff. It’s not a matter of “if” he makes it to the big leagues, but “when”. His 2023 season could determine when he’ll make it to the big leagues, but there’s a chance we’ll see the 21-year-old pitch in Triple-A at some point in 2023.

What’s next:

Our eighth-ranked prospect will be one of the Martinez’s, so stay tuned for that!
In case you missed it:
As always, you can follow me on Twitter @Brennan_L_D.