Fantasy baseball streaming starting pitchers: Aaron Nola’s new slider, is Tatsuya Imai fixed?

Welcome to your fantasy baseball starting pitcher happy place. This is a new column for me this year that will combine a few things I’ve done in the past. In this article, every Monday, you’ll not only get a list of my favorite streaming starting pitchers for the whole week, but underneath that, you’ll get a breakdown of a few pitchers who are making interesting changes to their pitch mix. Today I covered Joey Cantillo, Sean Burke, Jose Cabrera, and Brandon Young.

It’s a little bit of rankings and a little bit of analysis, and hopefully a lot of help for your teams.

As far as which pitchers on this list you’ll want to stream, your decisions will change based on your league type and settings. Since I’m listing starters for the whole week, I won’t be able to provide a detailed analysis for each one; I’ll highlight the matchup and offer some quick thoughts. As is usual with my articles, a streaming starter pitcher is rostered in less than 40% of Yahoo formats, so just keep that in mind as we’re going through because I won’t be mentioning pitchers who are rostered in more leagues than that. I also won’t be mentioning pitchers that I would not start in any format.

Check out this week’s MLB Power Rankings!

Starting Pitcher Streamers of the Week

I wrote about Sean Burke in this article last week, and I’m in for his two-start week this week. I like Peter Lambert as a low-ceiling streamer, and Robert Gasser is going to get another start at home against a reeling Reds lineup. If Elly De La Cruz and Eugenio Suarez are both out of the lineup, then I might move Gasser into a more confident territory. I know Eric Lauer has been good for the Dodgers, and I understand using him in a two-start week, but I’d rather avoid this one start in Sacramento if I could.

I think Griffin Jax needs to be rostered in more formats, so I’m going to keep listing him here. Cade Cavalli gets a recent matchup against the Red Sox, but Boston just swept the Yankees in a four-game series at home and are riding high, so that makes me a bit more concerned. Brandon Sproat has turned the corner lately, and I covered him below.

Joey Cantillo was in this article last week and needs to be rostered in more formats. I trust him for this start. I don’t trust Troy Melton has much in Yankee Stadium, but he has been pitching well lately, so I can see using him in 15-teamers. Colin Rea has also been solid lately when he’s gotten the opportunity, so I think you can trust him in deeper formats.

I’ve been a big Ian Seymour believer in the past, so I’m not going to abandon that belief after his best appearance of the season. Now is the time to jump back in. Dustin May had his past start pushed because of a back injury, and that scares me a little bit going into this start against the Braves.

Jake Bennett has turned in a few really good starts as he leans into an approach with fastballs up and changeups down. I think this could work. I’m rolling with him against the Angels. I also think Jack Perkins could be turning into a decent starter for the A’s. I just hate that this start is in Sacramento. I also like Christian Scott, but this is a bad matchup, and he hasn’t consistently gone five innings, which makes him tougher to roster.

Honestly, I’m not fairly confident in Kumar Rocker, but he just keeps delivering, so I think you can roll with him in deeper formats. I don’t believe in Brandon Young, but if Elly De La Cruz and Eugenio Suarez land on the IL, then I’d probably use him here. I liked Connor Prielipp‘s last start, but I would prefer not to start him in Yankee Stadium.

Now we get Eric Lauer at home against a Padres team that is really bad against lefties, so I’m far more interested in this matchup. We get decent second starts for Martin Perez and Robert Gasser as well, assuming Gasser remains in the rotation.

Starting Pitcher Pitch Mix Changes

Tatsuya Imai – Astros (Splitter Usage, Fastball Command)

Over the last two starts, Tatsuya Imai has allowed three runs on eight hits in 12 innings while striking out 21 and walking one. Understandably, people are getting excited, but is anything different? To be honest, not much.

Yes, his splitter usage is up to 10.3% over his last two starts from 3.6% on the season. However, that’s really the result of one game. In his start against Cleveland, he used the splitter 17% of the time, but it was down to 4% against the Tigers, so it’s hard to really say he’s using the splitter more often. On the year, the pitch is basically league average, with a league average zone rate and swinging strike rate. His changeup is seemingly better, but there’s also an argument that they’re the same pitch and sometimes get mislabeled, which connects to the larger issue of how hard Imai is to truly understand.

In his last two starts, his four-seam fastball has a 61% zone rate and 71% strike rate. Those are both significant improvements from his 48% zone rate and 60% strike rate on the season. His early called-strike rate on the four-seamer is actually the same, so he’s not getting ahead in the count more often. What’s happening is that hitters are putting his four-seamers in play more often in early-count situations. Imai is also using the fastball lower in the zone than he did before, perhaps to blend more with his slider.

Regardless, the fastball has still not been a great pitch for him. Even in these last two starts, he’s allowed a .294 average, 91.5 mph average exit velocity, 7.7% barrel rate, and 54% Ideal Contact Rate on his four-seamer while posting just a 5.1% swinging strike rate (SwStr%). In fact, he has just four whiffs COMBINED on his four-seamer in the last two starts out of his 36 total whiffs.

So that means much of his success is on the back of his slider. It makes sense because it’s a backward breaking slider that moved nearly five inches to his arm-side and barely drops. Hitters don’t see anything like it. In these last two starts, he’s gotten a 32.2% swinging strike rate on the pitch; however, that comes with just a 35% zone rate, so the success is predicated on hitters chasing out of the zone. In fact, his 8% middle-middle location on his slider over the last two starts is far above the 6.4% league average on sliders this season.

In short, Imai is not really throwing his splitter more. His fastball continues to get hit hard and not miss bats, and his slider is missing tons of bats, but it’s not commanded particularly well. All of this leads me to believe that this is more of a flukey stretch for Imai than anything. In part because he has a 38.2% PutAway Rate over his last two starts (which measures how often a two-strike pitch turns into a strikeout), and his season average is 20.9% and the league average is 18.9%. A 38.2% mark is wholly unsustainable. If you want to add him because we were intrigued by him in pre-season and he’s pitching well, go for it. But this doesn’t feel like a brand new pitcher to me.

He held a 67% putaway rate here after topping that with 73% in his previous outing. He entered this start with a 40% mark, and he won’t be so efficient in two-strike counts moving forward.

Aaron Nola – Phillies (New Slider, Four-Seam/Sinker Usage)

Aaron Nola is an interesting pitcher because we know how talented he has been, so his recent step back would lead us to believe he is “done” at just 33 years old. And while he’s throwing harder than he did last year. I’m not sure I’m ready to say that. Yes, he has a 5.58 ERA and 1.45 WHIP this season, but he also has a 3.94 SIERA, so is there an argument for him being better in the coming months?

On June 13th, Aaron Nola started using a gyro slider. It’s about 83 mph with one inch of vertical break and about four inches of horizontal movement, so nothing about it stands out, especially at that lower velocity. He’s using it almost exclusively to righties, where it’s posted a 99th percentile strike rate and an 18.2% SwStr%. He’s using it primarily when he’s behind in the count, which tells me that he’s trying to steal strikes with it, and the reason for that would be that he doesn’t want to use his four-seamer in those counts.

That makes some sense since his four-seamer has allowed a 50% Ideal Contact Rate and 21.4% barrel rate to righties this season. Nola will try to use it sometimes in two-strike counts, and it does have a 28.1% PutAway rate to righties (17.1% is league average for a four-seamer), but the pitch gets rocked when it is hit. The new slider could be a way to mitigate that damage, but since he doesn’t throw the slider to lefties, we still have a problem because his four-seamer also gets clobbered by lefties.

But, overall, we can see that Nola is trying to use his four-seamer less. Over his last six starts, he’s using his four-seamer just 18.7% of the time, down from 27.5% in his first 10 starts. He’s countered that by adding in the slider, using the sinker 5% more often and throwing to curveball 37% of the time, up from 32% in his first 10 starts.

He’s throwing the sinker more often in early-count situations to lefties and has also bumped up the curveball usage to lefties early in the count. Similar to righties, he has not only dialed back the four-seam usage overall to lefties but also tried to stop throwing it as much when he’s behind in the count. Over this stretch, he has a 4.80 ERA but a much better 1.27 WHIP and 23.8% strikeout rate, which pushed his K-BB% to 17% over his last six starts, compared to 14% in his first 10 starts. That’s not a nothing jump.

We’re not talking about Nola getting back to his peak, but I think continuing to hide his four-seamer and lean into his curveball makes sense for him. I’d like to see him do it even more, but that would put him back on the streaming radar in 12-team leagues and as a guy you can at least hold on your bench through tough starts in deeper formats. He’s a smart pitcher, so I’d bet on him continuing to make changes.

Brandon Sproat – Brewers (Fastball Usage, Sweeper Command)

We have to talk about the six innings of shutout ball against the Reds last week, where Sproat struck out 10, didn’t walk a batter, allowed one hit, and had 18 whiffs. We should also note that Sproat has not issued more than two walks in his last four starts. On Tuesday against the Reds, Sproat’s command of his four-seamer was exceptional, and he did a great job of keeping it at the top of the zone. The sweeper stayed low and away from righties, and he had four whiffs and a 38.5% CSW on that pitch. The curveball was always low and under the zone (sometimes too low), but we’d rather that than leave it up. He also mixed in sinkers and cutters to allow the four-seamer to play up more as a whiff pitch, and you can see how this can all work. His start before that at Cleveland was really just one bad inning, and the previous start in Sacramento was good, so maybe this is Sproat coming into his own?

If we look at his last four starts combined, he has a 3.48 ERA, 0.92 WHIP, 27% strikeout rate, and 15% SwStr%. We love all of that. Some of that could be the result of reshaping his pitch mix.

In his first 11 starts, he threw his cutter 27% of the time and his four-seamer just 18%. Over his last four, he’s 28% four-seamer and 19% cutter. Some of that could be that his cutter has been just an average pitch. On the year, it has an average strike rate, swinging strike rate, and Ideal Contact Rate allowed. It doesn’t give up tons of barrels and is a pitch he often used early in the count, but it also had just an average early called strike rate, so everything has been pretty average.

Over these last four starts, he’s turned to the four-seamer more and is trying to use it up in the zone more often. His high location rate on his four-seamer is 44.5% on the season, but it was 65.2% in this start against the Reds and 85.7% two starts ago against the Athletics, so it’s clear he’s trying to elevate it more often. He’s also seen improved zone rates on the four-seamer during this stretch, and the pitch has been a good two-strike pitch for him all season, so it makes sense to try and lean into it a bit more often.

He’s also doing a much better job of keeping his sweeper low in the zone. In his first 11 starts, he had a 73% low location on his sweeper, but that has jumped to 87.5% over his last four starts. He’s also using it in two-strike counts 58.3% of the time (up from 49%) and has a far lower zone rate, down to 25% from 43%. While that may seem like an odd approach, he’s basically realized that his sweeper is his best whiff pitch but also saw that it gave up a 12.5% barrel rate in his first 11 starts. His new approach to bury it low in the zone basically means that he’s going to get a whiff or a take on it, but hitters aren’t going to beat him on his sweeper.

He has the reverse issue with his curve, which he kept under the zone around 75% of the time in his first 11 starts but had just a 21% zone rate and 49% strike rate. He’s still keeping it low 67% of the time, but is also throwing it in the zone 33.3% of the time and getting a strike 66.7% of the time. Those are big improvements. It’s also led to him using the curve 59.3% of the time in two-strike counts, up from 48.5% earlier in the season.

All of which is to say that it seems like Brandon Sproat is starting to figure things out with his arsenal, optimizing his pitch mix for more whiffs and locating his secondary pitches more consistently. We may be seeing a breakout happen here.