Fantasy Baseball League Winners: Unlikely Aces Worth A Roster Spot? (Week 18)

Tommy Bell's weekly deep dive into three fantasy baseball starting pitchers to decide if their surprisingly good form merits a roster spot or staying on the waiver wire for Week 18 (2024).

Welcome back to another week of Unlikely Aces. We are a week into the unofficial "second half" of the season, but almost every MLB team has reached the 100-game mark, so we're well past halfway in most respects. With the real-life and fantasy trade deadlines looming, it's more important than ever to take advantage of any value that may still exist on waiver wires. So, let's try to do just that!

Each week, I'll take a look at three starters who have found recent success despite lesser outlooks across the fantasy landscape. By diving into some analytics, we can try to predict whether a back-end arm can potentially carry fantasy managers to glory or if the strong performances are more likely a flash in the pan.

Are these unlikely aces for real, or is it safe to leave them out on the waiver wire with negative regression surely coming in bunches quickly? Let's take a deeper look!

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Luis L. Ortiz, Pittsburgh Pirates

32% Rostered

After an up-and-down 2023 season with the Pirates, Luis Ortiz was relegated to a reliever role to start 2024, and his results were still a bit shaky. However, with his form looking up in June and the Pirates in need of an extra starter due to injuries, the right-hander got another shot as a starter, and to say he's taken advantage thus far would be an understatement.

Ortiz has thrown 24.2 innings in his four starts since the end of June, and he's sporting a matching 0.73 ERA and WHIP while walking just three batters, striking out 19, and not allowing a single home run in that span. He's become an elite addition to an already talented Pittsburgh rotation... But can it stick?

Dating back to his final start of the 2023 season, Luis Ortiz has thrown 5.0+ innings and allowed four or fewer hits in five consecutive starts, matching the second-longest such streak in franchise history 👏 pic.twitter.com/4a0Hmlr3SO

— Pittsburgh Pirates (@Pirates) July 21, 2024

The warning signs for the 25-year-old, if we're looking for them, would be a crazy low .224 BABIP with an unsustainable 88.9% LOB rate in his four starts. Ortiz's strikeout rate is still not elite at 21.3% in that span, but that number sounds better when you consider that his hard-hit rate has dropped all the way down to 20.9% in his four starts.

Ortiz is a ground ball pitcher (43.3% GB rate in his four starts) with awesome movement on his cutter, sinker, and slider. He's young enough to warrant an adjustment this year, and there's something to be said about having veteran Latin players in his clubhouse now with Martin Perez and Aroldis Chapman. I'm willing to ride Ortiz's success until he gives us reason to be concerned again. This is a guy Pittsburgh was VERY excited about last year, and we're finally seeing why.

Ryne Nelson, Arizona Diamondbacks

17% Rostered

A youngster in just his second full season as a major league pitcher, Ryne Nelson has been a relatively stable force in the Diamondbacks rotation this year. The 26-year-old has had a few hiccups, including a six-run outing in his final June start against the Twins, but he's in the midst of a strong four-game stretch to start July, and he'll throw once more on Wednesday evening just after I finish drafting this article.

In his four July starts thus far, Nelson is 2-0 with a 2.22 ERA with just four walks and one homer allowed through 24.1 innings pitched. He's also bumped up his strikeout rate a bit in this span, posting an 8.14 K/9 compared to just 6.09 K/9 through the end of June. Is it sustainable?

The 2019 draft pick out of Oregon had an unusually high .346 BABIP leading up to July, so it's great to see some positive regression come his way in the form of a .242 BABIP since then. The steep drop in hard-hit rate, much like Ortiz above, certainly helps that. There's plenty to like for Nelson if this change is legit!

Ryne Nelson, 97mph Paint. 🖌️🎨 pic.twitter.com/KpFcA90c2w

— Rob Friedman (@PitchingNinja) July 13, 2024

The "change" could be a big jump in fastball usage, as he's up to nearly 64% with his four-seamer compared to just 49.8% in the three months prior. Nelson has thrown fewer cutters and almost eliminated the curveball, so we'll see if that approach remains after the All-Star break.

All-in-all, it doesn't surprise me to see Nelson's recent success tied in with a jump in four-seam usage. That was the pitch that the analytics loved most when he made his debut in 2022. Perhaps he is finally trusting it enough, and maybe the BABIP will level back out, but the jump in strikeouts could remain. Pick up Nelson to see this through if he's still available.

Marco Gonzales, Pittsburgh Pirates

3% Rostered

Let's sandwich Nelson with two Pirates. This has quickly become an NL Wild Card article (yes, that's a subtle Pirates brag).

Marco Gonzales is a tougher case to crack, as injuries derailed his season in April. The southpaw started just three games for the Buccos to begin the year before getting shut down with a forearm strain. He finally returned just before the All-Star break and looked great against the White Sox. The veteran then doubled down with a fine showing against the best team in baseball, holding the Phillies to two earned runs through 4.2 innings.

It's likely a bit early to be jumping on the 32-year-old as a trustworthy fantasy option, but avoiding walks and long balls could prove valuable in deeper leagues. Gonzales will need to start getting a few more swings and misses with his changeup, which he's throwing around 40% of the time since his return, but he and the Pirates are clearly fond of that pitch, and his slider/curveball combination, along with it provides some intrigue.

Marco Gonzales, Nasty 81mph Changeup. 👌 pic.twitter.com/Uo8HjIp8sk

— Rob Friedman (@PitchingNinja) April 7, 2024

There's nothing overly concerning about Gonzales' underlying numbers, so if you notice the strikeout rate and/or innings pitch start to rise in his next start or two, it might be time to pick up the lefty for the home stretch. He should have plenty left in the tank, and he's the better option than Martin Perez when Jared Jones returns from injury. I could see Gonzales being a decent option in good matchups as we dig deep in August and September.

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